diff --git a/lib/data/provider/auth_fb.dart b/lib/data/provider/auth_fb.dart
index 15d9dc1..6062f1a 100644
--- a/lib/data/provider/auth_fb.dart
+++ b/lib/data/provider/auth_fb.dart
@@ -9,7 +9,7 @@ import 'package:fcs/domain/entities/user.dart';
 import 'package:fcs/domain/exceiptions/signin_exception.dart';
 import 'package:fcs/helpers/api_helper.dart';
 import 'package:fcs/helpers/firebase_helper.dart';
-import 'package:firebase_auth/firebase_auth.dart';
+import 'package:firebase_auth/firebase_auth.dart' as fb;
 import 'package:logging/logging.dart';
 
 class AuthFb {
@@ -18,17 +18,17 @@ class AuthFb {
   static final AuthFb instance = AuthFb._();
   AuthFb._();
 
-  StreamController<User> controller;
-  static final FirebaseAuth _fb = FirebaseAuth.instance;
-  static String _verificationId;
+  late StreamController<User?> controller;
+  static final fb.FirebaseAuth _fb = fb.FirebaseAuth.instance;
+  static String _verificationId = '';
 
   Future<fcs.AuthResult> sendSmsCodeToPhoneNumber(String phoneNumber) {
     Completer<fcs.AuthResult> completer = Completer();
     bool codeSentCompleted = false;
 
-    final PhoneVerificationCompleted verificationCompleted =
-        (AuthCredential credential) async {
-      AuthResult _authResult;
+    final fb.PhoneVerificationCompleted verificationCompleted =
+        (fb.AuthCredential credential) async {
+      fb.UserCredential _authResult;
       try {
         _authResult = await _fb.signInWithCredential(credential);
         print("PhoneVerificationCompleted :$_authResult");
@@ -48,23 +48,23 @@ class AuthFb {
           'Inside _sendCodeToPhoneNumber: signInWithPhoneNumber auto succeeded: ${_authResult.user}');
     };
 
-    final PhoneVerificationFailed verificationFailed =
-        (AuthException authException) async {
+    final fb.PhoneVerificationFailed verificationFailed =
+        (fb.FirebaseAuthException authException) async {
       print(
           'Phone number verification failed. Code: ${authException.code}. Message: ${authException.message}');
       completer.completeError(SigninException(
           "Phone number verification failed:${authException.message}"));
     };
 
-    final PhoneCodeSent codeSent =
-        (String verificationId, [int forceResendingToken]) async {
+    final fb.PhoneCodeSent codeSent =
+        (String verificationId, [int? forceResendingToken]) async {
       _verificationId = verificationId;
       print("codeSent  " + phoneNumber);
       codeSentCompleted = true;
       completer.complete(fcs.AuthResult(authStatus: AuthStatus.SMS_SENT));
     };
 
-    final PhoneCodeAutoRetrievalTimeout codeAutoRetrievalTimeout =
+    final fb.PhoneCodeAutoRetrievalTimeout codeAutoRetrievalTimeout =
         (String verificationId) {
       print("codeAutoRetrievalTimeout $verificationId ");
 
@@ -89,11 +89,11 @@ class AuthFb {
 
   Future<fcs.AuthResult> signInWithPhoneNumber(String smsCode) async {
     try {
-      final AuthCredential credential = PhoneAuthProvider.getCredential(
-        verificationId: _verificationId,
-        smsCode: smsCode,
-      );
-      AuthResult _authResult = await _fb.signInWithCredential(credential);
+      final fb.AuthCredential credential = fb.PhoneAuthProvider.credential(
+          verificationId: _verificationId, smsCode: smsCode);
+
+      fb.UserCredential _authResult =
+          await _fb.signInWithCredential(credential);
       if (_authResult == null) {
         throw SigninException("Sigin error!");
       }
@@ -105,19 +105,21 @@ class AuthFb {
   }
 
   Future<void> signout() async {
-    if (userListener != null) await userListener.cancel();
+    if (userListener != null) await userListener!.cancel();
     return _fb.signOut();
   }
 
   Future<void> _addUserToStream({bool refreshIdToken = false}) async {
-    FirebaseUser firebaseUser = await _fb.currentUser();
+    fb.User? firebaseUser = _fb.currentUser;
     if (firebaseUser == null) return null;
-    Map claims = await getClaims(refreshIdToken: refreshIdToken);
+    Map<dynamic, dynamic>? claims =
+        await getClaims(refreshIdToken: refreshIdToken);
 
     log.info("Claims:$claims");
+    if (claims == null) return;
 
     String cid = claims["cid"];
-    User user;
+    User? user;
     if (cid != null && cid != "") {
       user = await _getUserFromFirestore(cid);
     }
@@ -136,20 +138,20 @@ class AuthFb {
     controller.add(user);
   }
 
-  Future<User> _getUserFromFirestore(String userID) async {
-    DocumentSnapshot snap = await Firestore.instance
+  Future<User?> _getUserFromFirestore(String userID) async {
+    DocumentSnapshot snap = await FirebaseFirestore.instance
         .collection(user_collection)
-        .document(userID)
+        .doc(userID)
         .get();
     if (snap.exists) {
-      User user = User.fromMap(snap.data, snap.documentID);
+      User user = User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       return user;
     }
     return null;
   }
 
   Future<bool> isLogin() async {
-    final FirebaseUser firebaseUser = await _fb.currentUser();
+    final fb.User? firebaseUser = _fb.currentUser;
     return Future.value(firebaseUser != null);
   }
 
@@ -193,48 +195,50 @@ class AuthFb {
   }
 
   Stream<Setting> settings() async* {
-    Stream<DocumentSnapshot> snapshot = Firestore.instance
+    Stream<DocumentSnapshot> snapshot = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(setting_doc_id)
+        .doc(setting_doc_id)
         .snapshots();
 
     await for (var snap in snapshot) {
-      Setting setting = Setting.fromMap(snap.data);
+      Setting setting = Setting.fromMap(snap.data() as Map<String, dynamic>);
       yield setting;
     }
   }
 
-  Future<String> _getCurrentUserID() async {
-    FirebaseUser firebaseUser = await _fb.currentUser();
+  Future<String?> _getCurrentUserID() async {
+    fb.User? firebaseUser = _fb.currentUser;
     if (firebaseUser == null) return null;
-    Map claims = await getClaims();
+    Map? claims = await getClaims();
+    if (claims == null) return null;
     String cid = claims["cid"];
     return cid;
   }
 
   Future<void> _startUserListener() async {
-    if (userListener != null) userListener.cancel();
-    String _userID = await _getCurrentUserID();
+    if (userListener != null) userListener!.cancel();
+    String? _userID = await _getCurrentUserID();
     if (_userID == null) {
       return;
     }
 
-    Stream<DocumentSnapshot> snapshot = Firestore.instance
+    Stream<DocumentSnapshot> snapshot = FirebaseFirestore.instance
         .collection(user_collection)
-        .document(_userID)
+        .doc(_userID)
         .snapshots();
     userListener = snapshot.listen((snap) async {
-      User user = User.fromMap(snap.data, snap.documentID);
+      User user = User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
 
-      FirebaseUser firebaseUser = await _fb.currentUser();
+      fb.User? firebaseUser = _fb.currentUser;
       if (firebaseUser == null) {
-        userListener.cancel();
+        userListener?.cancel();
         return;
       }
       try {
         // get privilege from claim
-        IdTokenResult idToken = await firebaseUser.getIdToken(refresh: true);
-        String privileges = idToken.claims["pr"];
+        fb.IdTokenResult idToken = await firebaseUser.getIdTokenResult(true);
+
+        String privileges = idToken.claims?["pr"] ?? '';
         if (privileges != null && privileges != "") {
           user.privileges = privileges.split(":").toList();
         }
@@ -245,13 +249,13 @@ class AuthFb {
     });
   }
 
-  StreamSubscription<DocumentSnapshot> userListener;
-  Stream<User> user() {
+  StreamSubscription<DocumentSnapshot>? userListener;
+  Stream<User?> user() {
     // ignore: close_sinks
-    StreamSubscription<FirebaseUser> authListener;
+    StreamSubscription<fb.User?>? authListener;
 
     Future<void> _start() async {
-      authListener = _fb.onAuthStateChanged.listen((firebaseUser) async {
+      authListener = _fb.authStateChanges().listen((firebaseUser) {
         if (firebaseUser == null) {
           controller.add(null);
         } else {
@@ -263,10 +267,10 @@ class AuthFb {
 
     void _stop() {
       if (userListener != null) {
-        userListener.cancel();
+        userListener!.cancel();
       }
       if (authListener != null) {
-        authListener.cancel();
+        authListener!.cancel();
       }
     }
 
diff --git a/lib/data/provider/carton_data_provider.dart b/lib/data/provider/carton_data_provider.dart
index 7f74557..622b8c8 100644
--- a/lib/data/provider/carton_data_provider.dart
+++ b/lib/data/provider/carton_data_provider.dart
@@ -1,5 +1,4 @@
 import 'dart:async';
-import 'dart:convert';
 
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:fcs/domain/constants.dart';
@@ -36,7 +35,7 @@ class CartonDataProvider {
   }
 
   Future<List<Carton>> searchCarton(String term) async {
-    if (term == null || term == '') return List();
+    if (term == null || term == '') return [];
 
     // var bytes = utf8.encode(term);
     // var base64Str = base64.encode(bytes);
@@ -45,7 +44,7 @@ class CartonDataProvider {
 
     try {
       String path = "/$cartons_collection";
-      var querySnap = await Firestore.instance
+      var querySnap = await FirebaseFirestore.instance
           .collection(path)
           .where("carton_number", isEqualTo: term)
           .where("carton_type",
@@ -53,13 +52,11 @@ class CartonDataProvider {
           .where("status", isEqualTo: carton_packed_status)
           .where("is_deleted", isEqualTo: false)
           .orderBy("user_name")
-          .getDocuments();
-      return querySnap.documents
-          .map((e) => Carton.fromMap(e.data, e.documentID))
-          .toList();
+          .get();
+      return querySnap.docs.map((e) => Carton.fromMap(e.data(), e.id)).toList();
     } catch (e) {
       log.warning("carton error:" + e.toString());
-      return null;
+      return [];
     }
   }
 }
diff --git a/lib/data/provider/package_data_provider.dart b/lib/data/provider/package_data_provider.dart
index e0d99a2..8183eaa 100644
--- a/lib/data/provider/package_data_provider.dart
+++ b/lib/data/provider/package_data_provider.dart
@@ -56,8 +56,8 @@ class PackageDataProvider {
         token: await getToken());
   }
 
-  Future<List<Package>> ftsSearchPackage(String term) async {
-    if (term == null || term == '') return List();
+  Future<List<Package>?> ftsSearchPackage(String term) async {
+    if (term == null || term == '') return [];
 
     var bytes = utf8.encode(term);
     var base64Str = base64.encode(bytes);
@@ -72,7 +72,7 @@ class PackageDataProvider {
           "/api/fts/$packages_collection/$escapePackage/$limit", "GET",
           url: Config.instance.reportURL, token: await getToken());
 
-      if (data == null) return List();
+      if (data == null) return [];
 
       data.forEach((p) {
         var package = Package.fromJson(p);
@@ -86,7 +86,7 @@ class PackageDataProvider {
   }
 
   Future<List<Package>> searchPackage(String term) async {
-    if (term == null || term == '') return List();
+    if (term == null || term == '') return [];
 
     List<Package> packages = [];
 
diff --git a/lib/data/provider/rate_data_provider.dart b/lib/data/provider/rate_data_provider.dart
index c8c416e..0ffc089 100644
--- a/lib/data/provider/rate_data_provider.dart
+++ b/lib/data/provider/rate_data_provider.dart
@@ -16,33 +16,33 @@ class RateDataProvider {
   static final RateDataProvider instance = RateDataProvider._();
   RateDataProvider._();
 
-  StreamController<Rate> controller;
+  late StreamController<Rate> controller;
   static Rate _rate = Rate();
 
   Stream<Rate> _rateStream() async* {
-    Stream<DocumentSnapshot> snapshot = Firestore.instance
+    Stream<DocumentSnapshot> snapshot = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .snapshots();
     await for (var snap in snapshot) {
-      Rate rate = Rate.fromMap(snap.data);
+      Rate rate = Rate.fromMap(snap.data() as Map<String, dynamic>);
       yield rate;
     }
   }
 
   Stream<List<CargoType>> _cargoTypeStream() async* {
     List<CargoType> cargoTypes = [];
-    Stream<QuerySnapshot> snapshots = Firestore.instance
+    Stream<QuerySnapshot> snapshots = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .collection(cargo_types_collection)
         .where("custom_duty", isEqualTo: false)
         .snapshots();
 
     await for (var snaps in snapshots) {
       cargoTypes = [];
-      cargoTypes = snaps.documents.map((snap) {
-        return CargoType.fromMap(snap.data, snap.documentID);
+      cargoTypes = snaps.docs.map((snap) {
+        return CargoType.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       }).toList();
 
       yield cargoTypes;
@@ -51,17 +51,17 @@ class RateDataProvider {
 
   Stream<List<CargoType>> _customDutiesStream() async* {
     List<CargoType> customDuries = [];
-    Stream<QuerySnapshot> snapshots = Firestore.instance
+    Stream<QuerySnapshot> snapshots = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .collection(cargo_types_collection)
         .where("custom_duty", isEqualTo: true)
         .snapshots();
 
     await for (var snaps in snapshots) {
       customDuries = [];
-      customDuries = snaps.documents.map((snap) {
-        return CargoType.fromMap(snap.data, snap.documentID);
+      customDuries = snaps.docs.map((snap) {
+        return CargoType.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       }).toList();
       yield customDuries;
     }
@@ -69,25 +69,26 @@ class RateDataProvider {
 
   Stream<List<DiscountByWeight>> _discountByWeightStream() async* {
     List<DiscountByWeight> discountByWeight = [];
-    Stream<QuerySnapshot> snapshots = Firestore.instance
+    Stream<QuerySnapshot> snapshots = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .collection(discounts_by_weights_collection)
         .snapshots();
 
     await for (var snaps in snapshots) {
       discountByWeight = [];
-      discountByWeight = snaps.documents.map((snap) {
-        return DiscountByWeight.fromMap(snap.data, snap.documentID);
+      discountByWeight = snaps.docs.map((snap) {
+        return DiscountByWeight.fromMap(
+            snap.data() as Map<String, dynamic>, snap.id);
       }).toList();
       yield discountByWeight;
     }
   }
 
-  StreamSubscription<Rate> rateListener;
-  StreamSubscription<List<CargoType>> cargoListener;
-  StreamSubscription<List<CargoType>> customListener;
-  StreamSubscription<List<DiscountByWeight>> discountListener;
+  late StreamSubscription<Rate> rateListener;
+  late StreamSubscription<List<CargoType>> cargoListener;
+  late StreamSubscription<List<CargoType>> customListener;
+  late StreamSubscription<List<DiscountByWeight>> discountListener;
   Stream<Rate> rate() {
     Future<void> _start() async {
       rateListener = _rateStream().listen((rate) {
diff --git a/lib/data/provider/user_data_provider.dart b/lib/data/provider/user_data_provider.dart
index 99ec833..3fc8394 100644
--- a/lib/data/provider/user_data_provider.dart
+++ b/lib/data/provider/user_data_provider.dart
@@ -37,23 +37,23 @@ class UserDataProvider {
         payload: {"token": token}, token: await getToken());
   }
 
-  Future<User> findUser(String phoneNumber) async {
-    QuerySnapshot querySnap = await Firestore.instance
+  Future<User?> findUser(String phoneNumber) async {
+    QuerySnapshot querySnap = await FirebaseFirestore.instance
         .collection(user_collection)
         .where("phone_number", isEqualTo: phoneNumber)
         .limit(1)
-        .getDocuments();
+        .get();
 
-    if (querySnap.documents.length > 0) {
-      var snap = querySnap.documents.first;
-      User user = User.fromMap(snap.data, snap.documentID);
+    if (querySnap.docs.length > 0) {
+      var snap = querySnap.docs.first;
+      User user = User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       return user;
     }
     return null;
   }
 
   Future<List<User>> searchUser(String term) async {
-    if (term == null || term == '') return List();
+    if (term == null || term == '') return [];
 
     var bytes = utf8.encode(term);
     var base64Str = base64.encode(bytes);
@@ -68,7 +68,7 @@ class UserDataProvider {
           "/api/fts/$user_collection/$escapeBuyer/$limit", "GET",
           url: Config.instance.reportURL, token: await getToken());
 
-      if (data == null) return List();
+      if (data == null) return [];
 
       data.forEach((buyer) {
         var user = User.fromJson(buyer);
@@ -76,7 +76,7 @@ class UserDataProvider {
       });
     } catch (e) {
       log.warning("buyer error:" + e.toString());
-      return null;
+      // return null;
     }
     return users;
   }
diff --git a/lib/data/services/auth_imp.dart b/lib/data/services/auth_imp.dart
index 05b36ec..056907f 100644
--- a/lib/data/services/auth_imp.dart
+++ b/lib/data/services/auth_imp.dart
@@ -3,17 +3,16 @@ import 'package:fcs/domain/entities/auth_result.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/setting.dart';
 import 'package:fcs/domain/entities/user.dart';
-import 'package:flutter/material.dart';
 
 import 'auth_service.dart';
 
 class AuthServiceImp implements AuthService {
   AuthServiceImp({
-    @required this.authFb,
-    @required this.connectivity,
+    required this.authFb,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final AuthFb authFb;
 
   @override
@@ -32,7 +31,7 @@ class AuthServiceImp implements AuthService {
   }
 
   @override
-  Stream<User> getUserStream() {
+  Stream<User?> getUserStream() {
     return authFb.user();
   }
 
diff --git a/lib/data/services/auth_service.dart b/lib/data/services/auth_service.dart
index dad8ce7..a276495 100644
--- a/lib/data/services/auth_service.dart
+++ b/lib/data/services/auth_service.dart
@@ -11,6 +11,6 @@ abstract class AuthService {
   Future<void> updateProfileName(String newUserName);
   Future<void> updatePreferredCurrency(String currency);
   Future<bool> hasInvite();
-  Stream<User> getUserStream();
+  Stream<User?> getUserStream();
   Stream<Setting> getSetting();
 }
diff --git a/lib/data/services/carton_imp.dart b/lib/data/services/carton_imp.dart
index ba97084..402f48e 100644
--- a/lib/data/services/carton_imp.dart
+++ b/lib/data/services/carton_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/carton_data_provider.dart';
 import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
-import 'package:flutter/material.dart';
 
 import 'carton_service.dart';
 
 class CartonServiceImp implements CartonService {
   CartonServiceImp({
-    @required this.cartonDataProvider,
-    @required this.connectivity,
+    required this.cartonDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final CartonDataProvider cartonDataProvider;
 
   @override
diff --git a/lib/data/services/common_imp.dart b/lib/data/services/common_imp.dart
index 74e0654..cfc24e0 100644
--- a/lib/data/services/common_imp.dart
+++ b/lib/data/services/common_imp.dart
@@ -2,13 +2,12 @@ import 'package:fcs/data/provider/common_data_provider.dart';
 import 'package:fcs/domain/entities/discount.dart';
 import 'package:fcs/domain/entities/payment_method.dart';
 import 'package:fcs/domain/vo/message.dart';
-import 'package:flutter/material.dart';
 
 import 'common_service.dart';
 
 class CommonServiceImp implements CommonService {
   CommonServiceImp({
-    @required this.commonDataProvider,
+    required this.commonDataProvider,
   });
 
   final CommonDataProvider commonDataProvider;
diff --git a/lib/data/services/delivery_address_imp.dart b/lib/data/services/delivery_address_imp.dart
index 96d8a36..d60219a 100644
--- a/lib/data/services/delivery_address_imp.dart
+++ b/lib/data/services/delivery_address_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/delivery_address_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
-import 'package:flutter/material.dart';
 
 import 'delivery_address_service.dart';
 
 class DeliveryAddressImp implements DeliveryAddressService {
   DeliveryAddressImp({
-    @required this.connectivity,
-    @required this.deliveryAddressDataProvider,
+    required this.connectivity,
+    required this.deliveryAddressDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final DeliveryAddressDataProvider deliveryAddressDataProvider;
 
   @override
diff --git a/lib/data/services/fcs_shipment_imp.dart b/lib/data/services/fcs_shipment_imp.dart
index 6ffaafa..35e5071 100644
--- a/lib/data/services/fcs_shipment_imp.dart
+++ b/lib/data/services/fcs_shipment_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/fcs_shipment_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/fcs_shipment.dart';
-import 'package:flutter/material.dart';
 
 import 'fcs_shipment_service.dart';
 
 class FcsShipmentServiceImp implements FcsShipmentService {
   FcsShipmentServiceImp({
-    @required this.connectivity,
-    @required this.shipmentDataProvider,
+    required this.connectivity,
+    required this.shipmentDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final FcsShipmentDataProvider shipmentDataProvider;
 
   @override
diff --git a/lib/data/services/invoice_imp.dart b/lib/data/services/invoice_imp.dart
index c26dab4..de8e1d0 100644
--- a/lib/data/services/invoice_imp.dart
+++ b/lib/data/services/invoice_imp.dart
@@ -1,21 +1,17 @@
 import 'package:fcs/data/provider/invoice_data_provider.dart';
-import 'package:fcs/data/provider/shipment_data_provider.dart';
-import 'package:fcs/data/services/shipment_service.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/invoice.dart';
 import 'package:fcs/domain/entities/payment.dart';
-import 'package:fcs/domain/entities/shipment.dart';
-import 'package:flutter/material.dart';
 
 import 'invoice_service.dart';
 
 class InvoiceServiceImp implements InvoiceService {
   InvoiceServiceImp({
-    @required this.invoiceDataProvider,
-    @required this.connectivity,
+    required this.invoiceDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final InvoiceDataProvider invoiceDataProvider;
 
   @override
diff --git a/lib/data/services/package_imp.dart b/lib/data/services/package_imp.dart
index 75f0b56..f200147 100644
--- a/lib/data/services/package_imp.dart
+++ b/lib/data/services/package_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/package_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/package.dart';
-import 'package:flutter/material.dart';
 
 import 'package_service.dart';
 
 class PackageServiceImp implements PackageService {
   PackageServiceImp({
-    @required this.connectivity,
-    @required this.packageDataProvider,
+    required this.connectivity,
+    required this.packageDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final PackageDataProvider packageDataProvider;
 
   @override
@@ -30,7 +29,7 @@ class PackageServiceImp implements PackageService {
   }
 
   @override
-  Future<List<Package>> ftsSearchPackage(String term) {
+  Future<List<Package>?> ftsSearchPackage(String term) {
     return packageDataProvider.ftsSearchPackage(term);
   }
 
diff --git a/lib/data/services/package_service.dart b/lib/data/services/package_service.dart
index ca00c58..2d27585 100644
--- a/lib/data/services/package_service.dart
+++ b/lib/data/services/package_service.dart
@@ -7,7 +7,7 @@ abstract class PackageService {
   Future<void> deleteReceiving(Package package);
   Future<void> updateProcessing(Package package);
   Future<void> deleteProcessing(Package package);
-  Future<List<Package>> ftsSearchPackage(String term);
+  Future<List<Package>?> ftsSearchPackage(String term);
   Future<List<Package>> searchPackage(String term);
   Future<void> changeDeliveryAddress(String packageID, String deliveryID);
   Future<void> packageReturn(String packageID);
diff --git a/lib/data/services/rate_imp.dart b/lib/data/services/rate_imp.dart
index 6bea2ee..ad1d0e9 100644
--- a/lib/data/services/rate_imp.dart
+++ b/lib/data/services/rate_imp.dart
@@ -4,17 +4,16 @@ import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/discount_by_weight.dart';
 import 'package:fcs/domain/entities/custom_duty.dart';
 import 'package:fcs/domain/entities/rate.dart';
-import 'package:flutter/material.dart';
 
 import 'rate_service.dart';
 
 class RateServiceImp implements RateService {
   RateServiceImp({
-    @required this.rateDataProvider,
-    @required this.connectivity,
+    required this.rateDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final RateDataProvider rateDataProvider;
 
   @override
diff --git a/lib/data/services/services.dart b/lib/data/services/services.dart
index aee169b..b2e15d0 100644
--- a/lib/data/services/services.dart
+++ b/lib/data/services/services.dart
@@ -35,17 +35,18 @@ import 'user_service.dart';
 class Services {
   static final Services instance = Services._();
 
-  AuthService _authService;
-  UserService _userService;
-  PackageService _packageService;
-  MessagingService _messagingService;
-  CommonService _commonService;
-  FcsShipmentService _fcsShipmentService;
-  DeliveryAddressService _deliveryAddressService;
-  RateService _rateService;
-  ShipmentService _shipmentService;
-  CartonService _cartonService;
-  InvoiceService _invoiceService;
+  late AuthService _authService;
+  late UserService _userService;
+  late PackageService _packageService;
+  late MessagingService _messagingService;
+  late CommonService _commonService;
+  late FcsShipmentService _fcsShipmentService;
+  late DeliveryAddressService _deliveryAddressService;
+  late RateService _rateService;
+  late ShipmentService _shipmentService;
+  late CartonService _cartonService;
+  late InvoiceService _invoiceService;
+
   Services._() {
     _authService = AuthServiceImp(
       authFb: AuthFb.instance,
diff --git a/lib/data/services/shipment_imp.dart b/lib/data/services/shipment_imp.dart
index 8aeb11d..0b3a784 100644
--- a/lib/data/services/shipment_imp.dart
+++ b/lib/data/services/shipment_imp.dart
@@ -2,15 +2,14 @@ import 'package:fcs/data/provider/shipment_data_provider.dart';
 import 'package:fcs/data/services/shipment_service.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/shipment.dart';
-import 'package:flutter/material.dart';
 
 class ShipmentServiceImp implements ShipmentService {
   ShipmentServiceImp({
-    @required this.shipmentDataProvider,
-    @required this.connectivity,
+    required this.shipmentDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final ShipmentDataProvider shipmentDataProvider;
 
   @override
diff --git a/lib/data/services/user_imp.dart b/lib/data/services/user_imp.dart
index d3b7685..9b5305a 100644
--- a/lib/data/services/user_imp.dart
+++ b/lib/data/services/user_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/user_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/user.dart';
-import 'package:flutter/material.dart';
 
 import 'user_service.dart';
 
 class UserServiceImp implements UserService {
   UserServiceImp({
-    @required this.connectivity,
-    @required this.userDataProvider,
+    required this.connectivity,
+    required this.userDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final UserDataProvider userDataProvider;
 
   @override
@@ -30,7 +29,7 @@ class UserServiceImp implements UserService {
   }
 
   @override
-  Future<User> findUser(String phoneNumber) {
+  Future<User?> findUser(String phoneNumber) {
     return userDataProvider.findUser(phoneNumber);
   }
 
diff --git a/lib/data/services/user_service.dart b/lib/data/services/user_service.dart
index 168193d..0dd4297 100644
--- a/lib/data/services/user_service.dart
+++ b/lib/data/services/user_service.dart
@@ -4,7 +4,7 @@ abstract class UserService {
   Future<void> inviteUser(String userName, String phoneNumber);
   Future<void> deleteInvite(String phoneNumber);
   Future<void> acceptRequest(String userID);
-  Future<User> findUser(String phoneNumber);
+  Future<User?> findUser(String phoneNumber);
   Future<List<User>> searchUser(String term);
   Future<void> uploadMsgToken(String token);
   Future<void> removeMsgToken(String token);
diff --git a/lib/domain/entities/auth_result.dart b/lib/domain/entities/auth_result.dart
index dd989fd..5467733 100644
--- a/lib/domain/entities/auth_result.dart
+++ b/lib/domain/entities/auth_result.dart
@@ -1,9 +1,9 @@
 import 'auth_status.dart';
 
 class AuthResult {
-  AuthStatus authStatus;
-  String authErrorCode;
-  String authErrorMsg;
+  AuthStatus? authStatus;
+  String? authErrorCode;
+  String? authErrorMsg;
 
   AuthResult({this.authStatus, this.authErrorCode, this.authErrorMsg});
 }
diff --git a/lib/domain/entities/cargo_type.dart b/lib/domain/entities/cargo_type.dart
index 68ec494..0e165ea 100644
--- a/lib/domain/entities/cargo_type.dart
+++ b/lib/domain/entities/cargo_type.dart
@@ -1,28 +1,28 @@
 class CargoType {
-  String id;
-  String name;
+  String? id;
+  String? name;
   double rate;
   double weight;
   bool isChecked;
   int qty;
-  bool isCutomDuty;
+  bool? isCutomDuty;
   double customDutyFee;
-
-  double get calAmount => (calRate ?? 0) * (calWeight ?? 0);
-
   double calRate;
   double calWeight;
+
+  double get calAmount => calRate * calWeight;
+
   CargoType(
       {this.id,
       this.name,
-      this.rate,
-      this.weight,
-      this.calWeight,
-      this.calRate,
+      this.rate = 0,
+      this.weight = 0,
+      this.calWeight = 0,
+      this.calRate = 0,
       this.isChecked = false,
       this.qty = 0,
       this.isCutomDuty,
-      this.customDutyFee});
+      this.customDutyFee = 0});
 
   factory CargoType.fromMap(Map<String, dynamic> map, String id) {
     return CargoType(
@@ -52,7 +52,7 @@ class CargoType {
   }
 
   CargoType clone() {
-    return CargoType.fromMap(toMap(), this.id);
+    return CargoType.fromMap(toMap(), this.id!);
   }
 
   @override
@@ -63,7 +63,7 @@ class CargoType {
 
   @override
   String toString() {
-    return name;
+    return name ?? "";
   }
 
   bool isChangedForEdit(CargoType cargoType) {
diff --git a/lib/domain/entities/carton.dart b/lib/domain/entities/carton.dart
index 831adf2..8006051 100644
--- a/lib/domain/entities/carton.dart
+++ b/lib/domain/entities/carton.dart
@@ -9,61 +9,60 @@ import 'cargo_type.dart';
 import 'package.dart';
 
 class Carton {
-  String id;
-  String shipmentID;
-  String shipmentNumber;
-  String senderID;
-  String senderFCSID;
-  String senderName;
+  String? id;
+  String? shipmentID;
+  String? shipmentNumber;
+  String? senderID;
+  String? senderFCSID;
+  String? senderName;
 
-  String boxNumber;
-  String status;
-  String cargoDesc;
-  String desc;
+  String? boxNumber;
+  String? status;
+  String? cargoDesc;
+  String? desc;
   double width;
   double height;
   double length;
-  int shipmentWeight;
-  bool isChecked;
-  bool isShipmentCarton;
-  String cartonType;
-  String fcsID;
-  String userName;
-  String userID;
-  String fcsShipmentID;
-  String fcsShipmentNumber;
-  String mixCartonID;
-  String mixCartonNumber;
-  String cartonSizeID;
-  String cartonSizeName;
-  double cartonWeight;
+  int? shipmentWeight;
+  bool? isChecked;
+  bool? isShipmentCarton;
+  String? cartonType;
+  String? fcsID;
+  String? userName;
+  String? userID;
+  String? fcsShipmentID;
+  String? fcsShipmentNumber;
+  String? mixCartonID;
+  String? mixCartonNumber;
+  String? cartonSizeID;
+  String? cartonSizeName;
+  double? cartonWeight;
 
   int rate;
   int weight;
-  String packageType;
-  String pickUpID;
-  List<String> photos;
-  String remark;
-  DateTime arrivedDate;
-  String cartonNumber;
+  String? packageType;
+  String? pickUpID;
+  List<String> photos = [];
+  String? remark;
+  DateTime? arrivedDate;
+  String? cartonNumber;
 
   List<String> packageIDs;
   List<Package> packages;
-  List<CargoType> cargoTypes;
+  List<CargoType> cargoTypes = [];
 
-  DeliveryAddress deliveryAddress;
-  Shipment shipment;
+  DeliveryAddress? deliveryAddress;
+  Shipment? shipment;
 
   //for mix box
-  String mixBoxType;
+  String? mixBoxType;
   List<Carton> mixCartons;
   List<String> mixCartonIDs;
 
-  int get amount => rate != null && weight != null ? rate * weight : 0;
+  int get amount => rate != null && weight != null ? (rate * weight) : 0;
 
   // String get packageNumber =>
   //     shipmentNumber + "-" + receiverNumber + " #" + boxNumber;
-  double get price => rate.toDouble() * weight;
 
   double get actualWeight =>
       cargoTypes == null ? 0 : cargoTypes.fold(0, (p, e) => e.weight + p);
@@ -84,15 +83,15 @@ class Carton {
   /// getCargoTypeForCalWeight returns carton with shipment weight
   List<CargoType> getCargoTypeForCalWeight(double volumetricRatio) {
     // get shipment weight
-    double volume = (length ?? 0) * (width ?? 0) * (height ?? 0);
-    double sw = volume / volumetricRatio ?? 0;
+    double volume = length * width * height;
+    double sw = volume / volumetricRatio;
 
     // get actual weight
     double aw = cargoTypes.fold(0.0, (p, c) => p + c.weight);
     if (aw == 0 || sw == 0) return [];
 
     cargoTypes.forEach((e) {
-      double calWeight = aw > sw ? e.weight : e.weight / aw * sw;
+      double calWeight = aw > sw ? e.weight : (e.weight / aw) * sw;
       e.calWeight = calWeight;
     });
     return cargoTypes;
@@ -116,7 +115,7 @@ class Carton {
     double total = 0;
     cargoTypes.forEach((e) {
       double r =
-          e.rate - (discountByWeight != null ? discountByWeight.discount : 0);
+          e.rate - (discountByWeight != null ? (discountByWeight.discount) : 0);
       double amount = e.weight * r;
       total += amount;
     });
@@ -134,9 +133,9 @@ class Carton {
       this.senderName,
       this.boxNumber,
       this.desc,
-      this.width,
-      this.height,
-      this.length,
+      this.width = 0,
+      this.height = 0,
+      this.length = 0,
       this.shipmentWeight,
       this.isChecked = false,
       this.cartonType,
@@ -151,13 +150,13 @@ class Carton {
       this.status,
       this.arrivedDate,
       this.cargoDesc,
-      this.shipmentHistory,
-      this.packages,
-      this.cargoTypes,
+      this.shipmentHistory = const [],
+      this.packages = const [],
+      this.cargoTypes = const [],
       this.cartonNumber,
       this.fcsShipmentID,
       this.fcsShipmentNumber,
-      this.packageIDs,
+      this.packageIDs = const [],
       this.mixCartonID,
       this.mixCartonNumber,
       this.isShipmentCarton = false,
@@ -165,14 +164,14 @@ class Carton {
       this.cartonSizeID,
       this.cartonSizeName,
       this.mixBoxType,
-      this.mixCartons,
-      this.mixCartonIDs,
+      this.mixCartons = const [],
+      this.mixCartonIDs = const [],
       this.cartonWeight});
 
   Map<String, dynamic> toMap() {
-    List _cargoTypes = cargoTypes?.map((c) => c.toMap())?.toList() ?? [];
-    List _packages = packages?.map((c) => c.toJson())?.toList();
-    List _mixCartons = mixCartons?.map((c) => c.toJson())?.toList();
+    List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
+    List _packages = packages.map((c) => c.toJson()).toList();
+    List _mixCartons = mixCartons.map((c) => c.toJson()).toList();
     return {
       'id': id,
       'fcs_shipment_id': fcsShipmentID,
@@ -213,9 +212,9 @@ class Carton {
       shipmentNumber: map['shipment_number'],
       // receiverNumber: map['receiver_number'],
       boxNumber: map['box_number'],
-      length: double.tryParse(map['length']?.toString()),
-      width: double.tryParse(map['width']?.toString()),
-      height: double.tryParse(map['height']?.toString()),
+      length: double.tryParse(map['length'].toString()) ?? 0,
+      width: double.tryParse(map['width'].toString()) ?? 0,
+      height: double.tryParse(map['height'].toString()) ?? 0,
       userName: map['user_name'],
       fcsID: map['fcs_id'],
       cartonType: map['carton_type'],
@@ -242,8 +241,8 @@ class Carton {
 
   Map<String, dynamic> toJson() {
     List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
-    List _packages = packages?.map((c) => c.toJson())?.toList();
-    List _mixCartons = mixCartons?.map((c) => c.toJson())?.toList();
+    List _packages = packages.map((c) => c.toJson()).toList();
+    List _mixCartons = mixCartons.map((c) => c.toJson()).toList();
     return {
       'id': id,
       'fcs_shipment_id': fcsShipmentID,
diff --git a/lib/domain/entities/carton_size.dart b/lib/domain/entities/carton_size.dart
index 7d9f494..e9cd28b 100644
--- a/lib/domain/entities/carton_size.dart
+++ b/lib/domain/entities/carton_size.dart
@@ -1,10 +1,11 @@
 class CartonSize {
-  String id;
-  String name;
+  String? id;
+  String? name;
   double length;
   double width;
   double height;
-  CartonSize({this.id, this.name, this.length, this.width, this.height});
+  CartonSize(
+      {this.id, this.name, this.length = 0, this.width = 0, this.height = 0});
 
   Map<String, dynamic> toMap() {
     return {
@@ -27,19 +28,10 @@ class CartonSize {
   }
 
   @override
-  bool operator ==(other) {
-    if (identical(this, other)) {
-      return true;
-    }
-    return other.id == this.id;
-  }
+  bool operator ==(Object other) => other is CartonSize && other.id == id;
 
   @override
-  int get hashCode {
-    int result = 17;
-    result = 37 * result + id.hashCode;
-    return result;
-  }
+  int get hashCode => id.hashCode;
 
   bool isChangedForEdit(CartonSize cartonSize) {
     return cartonSize.name != this.name ||
diff --git a/lib/domain/entities/custom_duty.dart b/lib/domain/entities/custom_duty.dart
index fb2a3aa..6f033f0 100644
--- a/lib/domain/entities/custom_duty.dart
+++ b/lib/domain/entities/custom_duty.dart
@@ -1,11 +1,15 @@
 class CustomDuty {
-  String id;
-  String productType;
-  String desc;
+  String? id;
+  String? productType;
+  String? desc;
   double fee;
   double shipmentRate;
   CustomDuty(
-      {this.id, this.productType, this.desc, this.fee, this.shipmentRate});
+      {this.id,
+      this.productType,
+      this.desc,
+      this.fee = 0,
+      this.shipmentRate = 0});
 
   factory CustomDuty.fromMap(Map<String, dynamic> map, String id) {
     return CustomDuty(
diff --git a/lib/domain/entities/customer.dart b/lib/domain/entities/customer.dart
index 0fb51e7..6606f28 100644
--- a/lib/domain/entities/customer.dart
+++ b/lib/domain/entities/customer.dart
@@ -1,10 +1,8 @@
-
-
 class Customer {
-  String id;
-  String name;
-  String phoneNumber;
-  String status;
+  String? id;
+  String? name;
+  String? phoneNumber;
+  String? status;
 
   Customer({
     this.id,
diff --git a/lib/domain/entities/discount.dart b/lib/domain/entities/discount.dart
index cb2bda0..144bb9d 100644
--- a/lib/domain/entities/discount.dart
+++ b/lib/domain/entities/discount.dart
@@ -1,9 +1,9 @@
 class Discount {
-  String id;
-  String code;
-  String customerId;
-  String customerName;
-  String status;
+  String? id;
+  String? code;
+  String? customerId;
+  String? customerName;
+  String? status;
   double amount;
 
   Discount({
@@ -11,7 +11,7 @@ class Discount {
     this.code,
     this.customerId,
     this.customerName,
-    this.amount,
+    this.amount = 0,
     this.status,
   });
 
diff --git a/lib/domain/entities/discount_by_weight.dart b/lib/domain/entities/discount_by_weight.dart
index 3ff9a1d..92d46f0 100644
--- a/lib/domain/entities/discount_by_weight.dart
+++ b/lib/domain/entities/discount_by_weight.dart
@@ -1,9 +1,9 @@
 class DiscountByWeight {
-  String id;
+  String? id;
   double weight;
   double discount;
 
-  DiscountByWeight({this.id, this.weight, this.discount});
+  DiscountByWeight({this.id, this.weight = 0, this.discount = 0});
 
   factory DiscountByWeight.fromMap(Map<String, dynamic> map, String id) {
     return DiscountByWeight(
diff --git a/lib/domain/entities/faq.dart b/lib/domain/entities/faq.dart
index fe20f07..7deae33 100644
--- a/lib/domain/entities/faq.dart
+++ b/lib/domain/entities/faq.dart
@@ -1,16 +1,17 @@
 class FAQ {
-  String id;
-  int sn;
-  String questionEng;
-  String questionMm;
-  String answerEng;
-  String answerMm;
-  String pageLinkLabelEng;
-  String pageLinkLabelMm;
-  String pageLink;
+  String? id;
+  int? sn;
+  String? questionEng;
+  String? questionMm;
+  String? answerEng;
+  String? answerMm;
+  String? pageLinkLabelEng;
+  String? pageLinkLabelMm;
+  String? pageLink;
 
-  String question(bool isEng) => isEng ? questionEng : questionMm;
-  String answer(bool isEng) => isEng ? answerEng : answerMm;
+  String question(bool isEng) =>
+      isEng ? (questionEng ?? "") : (questionMm ?? "");
+  String answer(bool isEng) => isEng ? (answerEng ?? "") : (answerMm ?? "");
 
   FAQ(
       {this.id,
diff --git a/lib/domain/entities/fcs_shipment.dart b/lib/domain/entities/fcs_shipment.dart
index 37e2c71..794e65e 100644
--- a/lib/domain/entities/fcs_shipment.dart
+++ b/lib/domain/entities/fcs_shipment.dart
@@ -3,17 +3,18 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 import '../constants.dart';
 
 class FcsShipment {
-  String id;
-  String shipmentNumber;
-  DateTime cutoffDate;
-  String shipType;
-  DateTime arrivalDate;
-  DateTime departureDate;
-  String consignee;
-  String port;
-  String destination;
-  String status;
-  String reportName;
+  String? id;
+  String? shipmentNumber;
+  DateTime? cutoffDate;
+  String? shipType;
+  DateTime? arrivalDate;
+  DateTime? departureDate;
+  String? consignee;
+  String? port;
+  String? destination;
+  String? status;
+  String? reportName;
+
   FcsShipment({
     this.id,
     this.shipmentNumber,
@@ -51,10 +52,10 @@ class FcsShipment {
     return {
       "id": id,
       'shipment_number': shipmentNumber,
-      'cutoff_date': cutoffDate?.toUtc()?.toIso8601String(),
+      'cutoff_date': cutoffDate?.toUtc().toIso8601String(),
       'shipment_type': shipType,
-      'arrival_date': arrivalDate?.toUtc()?.toIso8601String(),
-      'departure_date': departureDate?.toUtc()?.toIso8601String(),
+      'arrival_date': arrivalDate?.toUtc().toIso8601String(),
+      'departure_date': departureDate?.toUtc().toIso8601String(),
       'consignee': consignee,
       'port': port,
       'destination': destination,
diff --git a/lib/domain/entities/invoice.dart b/lib/domain/entities/invoice.dart
index b614fcc..3ac1c9e 100644
--- a/lib/domain/entities/invoice.dart
+++ b/lib/domain/entities/invoice.dart
@@ -10,15 +10,15 @@ import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/domain/entities/shipment.dart';
 
 class Invoice {
-  String id;
-  String invoiceNumber;
-  DateTime invoiceDate;
-  String fcsShipmentID;
-  String userID;
-  String fcsID;
-  String userName;
-  String phoneNumber;
-  String status;
+  String? id;
+  String? invoiceNumber;
+  DateTime? invoiceDate;
+  String? fcsShipmentID;
+  String? userID;
+  String? fcsID;
+  String? userName;
+  String? phoneNumber;
+  String? status;
 
   double handlingFee;
   double deliveryFee;
@@ -30,9 +30,9 @@ class Invoice {
   List<CargoType> cargoTypes;
   List<Shipment> shipments;
   List<Payment> payments;
-  Discount discount;
-  PaymentMethod paymentMethod;
-  String invoiceURL;
+  Discount? discount;
+  PaymentMethod? paymentMethod;
+  String? invoiceURL;
 
   List<CargoType> getCargoTypes(Rate rate) {
     if (cargoTypes != null) return cargoTypes;
@@ -40,7 +40,7 @@ class Invoice {
     List<CargoType> _cargoTypes = [];
     double totalCalWeight = 0;
     cartons.forEach((carton) {
-      if (carton.isChecked) {
+      if (carton.isChecked ?? false) {
         var _cartonsTypes =
             carton.getCargoTypeForCalWeight(rate.volumetricRatio);
         _cartonsTypes.forEach((ct) {
@@ -68,15 +68,15 @@ class Invoice {
 
   double getTotal(Rate rate) {
     List<CargoType> cargoTypes = getCargoTypes(rate);
-    var total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
+    double total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
     return total;
   }
 
-  double get balance => (amount ?? 0) - (paidAmount ?? 0);
+  double get balance => amount - paidAmount;
 
   double getNetAmount(Rate rate) {
     List<CargoType> cargoTypes = getCargoTypes(rate);
-    var total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
+    double total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
     total += getCustomFee();
     total += getDeliveryFee();
     total += getHandlingFee();
@@ -85,13 +85,13 @@ class Invoice {
   }
 
   double getHandlingFee() {
-    return shipments?.where((sh) => sh.isSelected ?? false)?.fold(0, (p, s) {
-      return p + (s?.handlingFee ?? 0) - (s?.paidHandlingFee ?? 0);
-    });
+    return shipments
+        .where((sh) => sh.isSelected)
+        .fold(0, (p, s) => p + (s.handlingFee - s.paidHandlingFee));
   }
 
   double getTotalBalance(Rate rate) {
-    return getNetAmount(rate) - (paidAmount ?? 0);
+    return getNetAmount(rate) - paidAmount;
   }
 
   double getCustomFee() {
@@ -102,7 +102,7 @@ class Invoice {
     return deliveryFee == null ? 0 : deliveryFee;
   }
 
-  double getDiscount() => discount == null ? 0 : discount.amount;
+  double getDiscount() => discount == null ? 0 : discount!.amount;
 
   Invoice(
       {this.id,
@@ -111,19 +111,19 @@ class Invoice {
       this.fcsID,
       this.userName,
       this.phoneNumber,
-      this.amount,
-      this.paidAmount,
+      this.amount = 0,
+      this.paidAmount = 0,
       this.discount,
       this.status,
-      this.customDuties,
-      this.cartons,
-      this.cargoTypes,
-      this.handlingFee,
-      this.deliveryFee,
+      this.customDuties = const [],
+      this.cartons = const [],
+      this.cargoTypes = const [],
+      this.handlingFee = 0,
+      this.deliveryFee = 0,
       this.fcsShipmentID,
-      this.shipments,
+      this.shipments = const [],
       this.invoiceURL,
-      this.payments,
+      this.payments = const [],
       this.paymentMethod});
 
   factory Invoice.fromMap(Map<String, dynamic> map, String docID) {
@@ -153,7 +153,7 @@ class Invoice {
     return Invoice(
       id: docID,
       invoiceNumber: map['invoice_number'],
-      invoiceDate: invd?.toDate(),
+      invoiceDate: invd.toDate(),
       userName: map['user_name'],
       fcsID: map['fcs_id'],
       phoneNumber: map['phone_number'],
@@ -174,12 +174,12 @@ class Invoice {
 
   Map<String, dynamic> toMap() {
     List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
-    List _customDuties = customDuties?.map((c) => c.toMap())?.toList();
-    List _cartons = cartons?.map((c) => c.toMap())?.toList() ?? [];
-    List _shipments = shipments?.map((s) => s.toMap())?.toList() ?? [];
+    List _customDuties = customDuties.map((c) => c.toMap()).toList();
+    List _cartons = cartons.map((c) => c.toMap()).toList();
+    List _shipments = shipments.map((s) => s.toMap()).toList();
     return {
       "id": id,
-      "invoice_date": invoiceDate?.toUtc()?.toIso8601String(),
+      "invoice_date": invoiceDate?.toUtc().toIso8601String(),
       "user_id": userID,
       "user_name": userName,
       "invoice_number": invoiceNumber,
diff --git a/lib/domain/entities/market.dart b/lib/domain/entities/market.dart
index 0b7ebec..f12c955 100644
--- a/lib/domain/entities/market.dart
+++ b/lib/domain/entities/market.dart
@@ -1,11 +1,8 @@
 class Market {
-  String id;
-  String name;
+  String? id;
+  String? name;
 
-  Market({
-    this.id,
-    this.name,
-  });
+  Market({this.id, this.name});
 
   Map<String, dynamic> toMap() {
     return {
diff --git a/lib/domain/entities/package.dart b/lib/domain/entities/package.dart
index 9eb3249..c583de1 100644
--- a/lib/domain/entities/package.dart
+++ b/lib/domain/entities/package.dart
@@ -5,35 +5,35 @@ import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/domain/vo/shipment_status.dart';
 
 class Package {
-  String id;
-  String trackingID;
-  String userID;
-  String fcsID;
-  String userName;
-  String phoneNumber;
-  DateTime currentStatusDate;
+  String? id;
+  String? trackingID;
+  String? userID;
+  String? fcsID;
+  String? userName;
+  String? phoneNumber;
+  DateTime? currentStatusDate;
   List<String> photoUrls;
   List<ShipmentStatus> shipmentHistory;
-  String desc;
+  String? desc;
 
-  String status;
-  String shipmentNumber;
-  String senderFCSID;
-  String senderName;
-  String senderPhoneNumber;
-  String boxNumber;
-  String cargoDesc;
-  String market;
+  String? status;
+  String? shipmentNumber;
+  String? senderFCSID;
+  String? senderName;
+  String? senderPhoneNumber;
+  String? boxNumber;
+  String? cargoDesc;
+  String? market;
   bool isChecked;
 
   int rate;
   int weight;
-  String packageType;
-  String pickUpID;
-  List<String> photos;
-  String remark;
-  DateTime arrivedDate;
-  DeliveryAddress deliveryAddress;
+  String? packageType;
+  String? pickUpID;
+  // List<String> photos;
+  String? remark;
+  DateTime? arrivedDate;
+  DeliveryAddress? deliveryAddress;
 
   //for packages in processing
   List<File> photoFiles;
@@ -42,35 +42,34 @@ class Package {
 
   double get price => rate.toDouble() * weight;
 
-  Package({
-    this.id,
-    this.trackingID,
-    this.userID,
-    this.userName,
-    this.fcsID,
-    this.phoneNumber,
-    this.shipmentNumber,
-    this.senderFCSID,
-    this.senderName,
-    this.boxNumber,
-    this.rate,
-    this.weight,
-    this.packageType,
-    this.pickUpID,
-    this.remark,
-    this.status,
-    this.arrivedDate,
-    this.cargoDesc,
-    this.market,
-    this.shipmentHistory,
-    this.currentStatusDate,
-    this.photoUrls,
-    this.desc,
-    this.deliveryAddress,
-    this.isChecked = false,
-    this.photoFiles,
-    this.senderPhoneNumber
-  });
+  Package(
+      {this.id,
+      this.trackingID,
+      this.userID,
+      this.userName,
+      this.fcsID,
+      this.phoneNumber,
+      this.shipmentNumber,
+      this.senderFCSID,
+      this.senderName,
+      this.boxNumber,
+      this.rate = 0,
+      this.weight = 0,
+      this.packageType,
+      this.pickUpID,
+      this.remark,
+      this.status,
+      this.arrivedDate,
+      this.cargoDesc,
+      this.market,
+      this.shipmentHistory = const [],
+      this.currentStatusDate,
+      this.photoUrls = const [],
+      this.desc,
+      this.deliveryAddress,
+      this.isChecked = false,
+      this.photoFiles = const [],
+      this.senderPhoneNumber});
 
   factory Package.fromMap(Map<String, dynamic> map, String docID) {
     var _currentStatusDate = (map['status_date'] as Timestamp);
@@ -98,9 +97,7 @@ class Package {
         senderName: map['sender_name'],
         senderPhoneNumber: map['sender_phone_number'],
         deliveryAddress: _da,
-        currentStatusDate: _currentStatusDate != null
-            ? _currentStatusDate.toDate().toLocal()
-            : null,
+        currentStatusDate: _currentStatusDate.toDate().toLocal(),
         photoUrls: _photoUrls,
         shipmentHistory: _shipmentStatus);
   }
diff --git a/lib/domain/entities/payment.dart b/lib/domain/entities/payment.dart
index d30eebc..feaeaca 100644
--- a/lib/domain/entities/payment.dart
+++ b/lib/domain/entities/payment.dart
@@ -1,11 +1,11 @@
 import 'package:cloud_firestore/cloud_firestore.dart';
 
 class Payment {
-  String id;
-  String invoiceID;
-  DateTime paymentDate;
-  String paymentReceiptURL;
-  String status;
+  String? id;
+  String? invoiceID;
+  DateTime? paymentDate;
+  String? paymentReceiptURL;
+  String? status;
   double amount;
 
   Payment(
@@ -14,13 +14,13 @@ class Payment {
       this.paymentDate,
       this.paymentReceiptURL,
       this.status,
-      this.amount});
+      this.amount = 0});
 
   factory Payment.fromMap(Map<String, dynamic> map, String id) {
     var _paymentDate = (map['payment_date'] as Timestamp);
     return Payment(
       id: id,
-      paymentDate: _paymentDate?.toDate(),
+      paymentDate: _paymentDate.toDate(),
       paymentReceiptURL: map['payment_receipt_url'],
       status: map['status'],
       amount: map['amount']?.toDouble() ?? 0,
@@ -31,7 +31,7 @@ class Payment {
     return {
       "id": id,
       "invoice_id": invoiceID,
-      'payment_date': paymentDate?.toUtc()?.toIso8601String(),
+      'payment_date': paymentDate?.toUtc().toIso8601String(),
       'payment_receipt_url': paymentReceiptURL,
       'status': status,
       'amount': amount,
@@ -39,7 +39,7 @@ class Payment {
   }
 
   Payment clone() {
-    return Payment.fromMap(toMap(), this.id);
+    return Payment.fromMap(toMap(), this.id!);
   }
 
   @override
diff --git a/lib/domain/entities/payment_method.dart b/lib/domain/entities/payment_method.dart
index 50cf277..109ad16 100644
--- a/lib/domain/entities/payment_method.dart
+++ b/lib/domain/entities/payment_method.dart
@@ -1,11 +1,11 @@
 class PaymentMethod {
-  String id;
-  String name;
-  String accountName;
-  String account;
-  String phone;
-  String email;
-  String link;
+  String? id;
+  String? name;
+  String? accountName;
+  String? account;
+  String? phone;
+  String? email;
+  String? link;
 
   PaymentMethod(
       {this.id,
diff --git a/lib/domain/entities/processing.dart b/lib/domain/entities/processing.dart
index 0006183..0c1a165 100644
--- a/lib/domain/entities/processing.dart
+++ b/lib/domain/entities/processing.dart
@@ -1,15 +1,15 @@
 import 'package:fcs/domain/entities/package.dart';
 
 class Processing {
-  String id;
+  String? id;
   //for consignee
-  String userID;
-  String userName;
-  String userPhoneNumber;
+  String? userID;
+  String? userName;
+  String? userPhoneNumber;
   //for shipper
-  String fcsID;
-  String shipperName;
-  String shipperPhoneNumber;
+  String? fcsID;
+  String? shipperName;
+  String? shipperPhoneNumber;
 
   List<Package> packages;
 
@@ -21,7 +21,7 @@ class Processing {
       this.fcsID,
       this.shipperName,
       this.shipperPhoneNumber,
-      this.packages});
+      this.packages = const []});
 
   @override
   bool operator ==(Object other) => other is Processing && other.id == id;
diff --git a/lib/domain/entities/rate.dart b/lib/domain/entities/rate.dart
index f5682e1..566d827 100644
--- a/lib/domain/entities/rate.dart
+++ b/lib/domain/entities/rate.dart
@@ -1,4 +1,3 @@
-
 import 'package:fcs/domain/entities/discount_by_weight.dart';
 
 import 'cargo_type.dart';
@@ -11,26 +10,25 @@ class Rate {
   double diffDiscountWeight;
   double diffWeightRate;
 
-  List<CargoType> cargoTypes;
-  List<CargoType> customDuties;
-  List<DiscountByWeight> discountByWeights;
+  List<CargoType> cargoTypes = [];
+  List<CargoType> customDuties = [];
+  List<DiscountByWeight> discountByWeights = [];
 
   DiscountByWeight getDiscountByWeight(double weight) {
     discountByWeights.sort((d1, d2) => d2.weight.compareTo(d1.weight));
-    return discountByWeights.firstWhere((e) => e.weight < weight,
-        orElse: () => null);
+    return discountByWeights.firstWhere((e) => e.weight < weight);
   }
 
-  CargoType get defaultCargoType => cargoTypes == null
+  CargoType? get defaultCargoType => cargoTypes == null
       ? null
       : cargoTypes.firstWhere((e) => e.name == "General");
 
   Rate(
-      {this.deliveryFee,
-      this.freeDeliveryWeight,
-      this.volumetricRatio,
-      this.diffDiscountWeight,
-      this.diffWeightRate});
+      {this.deliveryFee = 0,
+      this.freeDeliveryWeight = 0,
+      this.volumetricRatio = 0,
+      this.diffDiscountWeight = 0,
+      this.diffWeightRate = 0});
 
   factory Rate.fromMap(Map<String, dynamic> map) {
     return Rate(
diff --git a/lib/domain/entities/receipt.dart b/lib/domain/entities/receipt.dart
index 6fffbbe..70f59f5 100644
--- a/lib/domain/entities/receipt.dart
+++ b/lib/domain/entities/receipt.dart
@@ -1,9 +1,9 @@
 class Receipt {
-  String id;
-  int amount;
-  String date;
-  String status;
-  String fileUrl;
+  String? id;
+  int? amount = 0;
+  String? date;
+  String? status;
+  String? fileUrl;
 
   Receipt({this.id, this.amount, this.date, this.status, this.fileUrl});
 }
diff --git a/lib/domain/entities/setting.dart b/lib/domain/entities/setting.dart
index 8f594bb..c0aefe1 100644
--- a/lib/domain/entities/setting.dart
+++ b/lib/domain/entities/setting.dart
@@ -9,21 +9,20 @@ List<Day> dayLists = [
 ];
 
 class Setting {
-  final int supportBuildNum;
-
+  final int? supportBuildNum;
   // contact page
-  String usaAddress;
-  String mmAddress;
-  String usaContactNumber;
-  String mmContactNumber;
-  String emailAddress;
-  String facebookLink;
-  bool inviteRequired;
-  String appUrl;
-  final String termsEng;
-  final String termsMm;
-  String about;
-  String courierWebsite;
+  String? usaAddress;
+  String? mmAddress;
+  String? usaContactNumber;
+  String? mmContactNumber;
+  String? emailAddress;
+  String? facebookLink;
+  bool? inviteRequired;
+  String? appUrl;
+  final String? termsEng;
+  final String? termsMm;
+  String? about;
+  String? courierWebsite;
 
   List<String> shipmentTypes;
 
@@ -40,7 +39,7 @@ class Setting {
       this.termsEng,
       this.termsMm,
       this.about,
-      this.shipmentTypes,
+      this.shipmentTypes = const [],
       this.courierWebsite});
 
   factory Setting.fromMap(Map<String, dynamic> map) {
@@ -76,9 +75,9 @@ class Setting {
 }
 
 class Day {
-  int id;
-  String name;
-  bool isChecked = false;
+  int? id;
+  String? name;
+  bool? isChecked = false;
   Day({this.id, this.name, this.isChecked});
 
   @override
diff --git a/lib/domain/entities/shipment.dart b/lib/domain/entities/shipment.dart
index 7b837df..2d4cabc 100644
--- a/lib/domain/entities/shipment.dart
+++ b/lib/domain/entities/shipment.dart
@@ -4,35 +4,35 @@ import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
 
 class Shipment {
-  String id;
-  String shipmentNumber;
-  String shipmentType;
-  DeliveryAddress pickupAddress;
-  DateTime pickupDate;
-  String pickupTimeStart;
-  String pickupTimeEnd;
+  String? id;
+  String? shipmentNumber;
+  String? shipmentType;
+  DeliveryAddress? pickupAddress;
+  DateTime? pickupDate;
+  String? pickupTimeStart;
+  String? pickupTimeEnd;
 
-  String userName;
-  String userID;
-  String phoneNumber;
-  int numberOfPackage;
-  int weight;
-  double handlingFee;
-  double paidHandlingFee;
-  String address;
-  String status;
+  String? userName;
+  String? userID;
+  String? phoneNumber;
+  int numberOfPackage = 0;
+  int weight = 0;
+  double handlingFee = 0;
+  double paidHandlingFee = 0;
+  String? address;
+  String? status;
   bool isCourier;
   int radioIndex;
   List<Carton> boxes;
 
-  String pickupUserID;
-  String pickupUserName;
-  String pickupUserPhoneNumber;
+  String? pickupUserID;
+  String? pickupUserName;
+  String? pickupUserPhoneNumber;
 
-  String fcsShipmentID;
-  String fcsShipmentNumber;
-  String shipmentLabelUrl;
-  bool isSelected;
+  String? fcsShipmentID;
+  String? fcsShipmentNumber;
+  String? shipmentLabelUrl;
+  bool isSelected = false;
 
   Shipment(
       {this.id,
@@ -43,28 +43,28 @@ class Shipment {
       this.phoneNumber,
       this.pickupTimeStart,
       this.pickupTimeEnd,
-      this.numberOfPackage,
-      this.weight,
-      this.handlingFee,
-      this.paidHandlingFee,
+      this.numberOfPackage = 0,
+      this.weight = 0,
+      this.handlingFee = 0,
+      this.paidHandlingFee = 0,
       this.address,
       this.status,
       this.pickupDate,
       this.isCourier = false,
       this.radioIndex = 1,
-      this.pickupAddress,
+      required this.pickupAddress,
       this.pickupUserID,
       this.pickupUserName,
       this.pickupUserPhoneNumber,
       this.fcsShipmentID,
       this.fcsShipmentNumber,
       this.shipmentLabelUrl,
-      this.boxes});
+      this.boxes = const []});
 
-  int get last => DateTime.now().difference(pickupDate).inDays;
+  // int get last => DateTime.now().difference(pickupDate).inDays;
 
-  double get totalWeight => boxes?.fold(0, (p, e) => p + e.actualWeight);
-  int get totalCount => boxes?.length;
+  double get totalWeight => boxes.fold(0, (p, e) => p + e.actualWeight);
+  int get totalCount => boxes.length;
 
   bool get isPending => status == shipment_pending_status;
   bool get isAssigned => status == shipment_assigned_status;
@@ -100,15 +100,15 @@ class Shipment {
   }
 
   Map<String, dynamic> toMap() {
-    List _boxes = boxes?.map((l) => l.toMap())?.toList() ?? [];
+    List _boxes = boxes.map((l) => l.toMap()).toList();
 
     return {
       "id": id,
       'user_id': userID,
       'cartons': _boxes,
       'shipment_type': shipmentType,
-      'pickup_address': pickupAddress.toMap(),
-      "pickup_date": pickupDate?.toUtc()?.toIso8601String(),
+      'pickup_address': pickupAddress?.toMap(),
+      "pickup_date": pickupDate?.toUtc().toIso8601String(),
       'pickup_time_start': pickupTimeStart,
       'pickup_time_end': pickupTimeEnd,
       'pickup_user_id': pickupUserID,
diff --git a/lib/domain/entities/user.dart b/lib/domain/entities/user.dart
index 6ada508..ae917fe 100644
--- a/lib/domain/entities/user.dart
+++ b/lib/domain/entities/user.dart
@@ -9,18 +9,19 @@ DateFormat timeFormat = DateFormat("HH:mm");
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class User {
-  String id;
-  String name;
-  String phoneNumber;
-  String status;
-  String fcsID;
-  DateTime lastMessageTime;
-  String lastMessage;
-  int userUnseenCount;
-  int fcsUnseenCount;
-  String preferCurrency;
+  String? id;
+  String? name;
+  String? phoneNumber;
+  String? status;
+  String? fcsID;
+  DateTime? lastMessageTime;
+  String? lastMessage;
+  int? userUnseenCount;
+  int? fcsUnseenCount;
+  String? preferCurrency;
 
-  String get initial => name != null && name != "" ? name.substring(0, 1) : "?";
+  String get initial =>
+      name != null && name != "" ? name!.substring(0, 1) : "?";
 
   String get getLastMessage {
     var msg = lastMessage ?? "Say hi to $name";
@@ -31,27 +32,31 @@ class User {
   String get getLastMessageTime {
     if (lastMessageTime == null) return "";
     DateTime today = DateTime.now();
-    if (lastMessageTime.year == today.year &&
-        lastMessageTime.month == today.month &&
-        lastMessageTime.day == today.day) {
-      return timeFormat.format(lastMessageTime);
+    if (lastMessageTime!.year == today.year &&
+        lastMessageTime!.month == today.month &&
+        lastMessageTime!.day == today.day) {
+      return timeFormat.format(lastMessageTime!);
     } else {
-      return dateFormat.format(lastMessageTime);
+      return dateFormat.format(lastMessageTime!);
     }
   }
 
   String get getUserUnseenCount => userUnseenCount != null
-      ? userUnseenCount > 100 ? "99+" : userUnseenCount.toString()
+      ? userUnseenCount! > 100
+          ? "99+"
+          : userUnseenCount.toString()
       : "0";
   String get getFcsUnseenCount => fcsUnseenCount != null
-      ? fcsUnseenCount > 100 ? "99+" : fcsUnseenCount.toString()
+      ? fcsUnseenCount! > 100
+          ? "99+"
+          : fcsUnseenCount.toString()
       : "0";
 
   List<String> privileges = [];
 
-  String get phone => phoneNumber != null && phoneNumber.startsWith("959")
-      ? "0${phoneNumber.substring(2)}"
-      : phoneNumber;
+  String get phone => phoneNumber != null && phoneNumber!.startsWith("959")
+      ? "0${phoneNumber!.substring(2)}"
+      : phoneNumber!;
   bool get joined => status != null && status == user_joined_status;
   bool get invited => status != null && status == user_invited_status;
   bool get requested => status != null && status == user_requested_status;
@@ -64,7 +69,7 @@ class User {
       this.phoneNumber,
       this.fcsID,
       this.status,
-      this.privileges,
+      this.privileges = const [],
       this.lastMessage,
       this.lastMessageTime,
       this.userUnseenCount,
diff --git a/lib/domain/exceiptions/server_exceptions.dart b/lib/domain/exceiptions/server_exceptions.dart
index a76ba67..7436d0b 100644
--- a/lib/domain/exceiptions/server_exceptions.dart
+++ b/lib/domain/exceiptions/server_exceptions.dart
@@ -1,12 +1,12 @@
 
 class ServerException  {
   @override
-  List<Object> get props => null;
+  List<Object>? get props => null;
 
   call() {
     return null;
   }
 
   @override
-  bool get stringify => null;
+  bool? get stringify => null;
 }
diff --git a/lib/domain/vo/contact.dart b/lib/domain/vo/contact.dart
index 5df67a2..2037ddf 100644
--- a/lib/domain/vo/contact.dart
+++ b/lib/domain/vo/contact.dart
@@ -1,12 +1,12 @@
 import 'package:fcs/domain/entities/setting.dart';
 
 class Contact {
-  String usaAddress;
-  String mmAddress;
-  String usaContactNumber;
-  String mmContactNumber;
-  String emailAddress;
-  String facebookLink;
+  String? usaAddress;
+  String? mmAddress;
+  String? usaContactNumber;
+  String? mmContactNumber;
+  String? emailAddress;
+  String? facebookLink;
 
   Contact({
     this.usaAddress,
diff --git a/lib/domain/vo/delivery_address.dart b/lib/domain/vo/delivery_address.dart
index 93e7960..b212ebc 100644
--- a/lib/domain/vo/delivery_address.dart
+++ b/lib/domain/vo/delivery_address.dart
@@ -1,13 +1,14 @@
 class DeliveryAddress {
-  String id;
-  String fullName;
-  String addressLine1;
-  String addressLine2;
-  String city;
-  String state;
-  String phoneNumber;
+  String? id;
+  String? fullName;
+  String? addressLine1;
+  String? addressLine2;
+  String? city;
+  String? state;
+  String? phoneNumber;
   bool isDefault;
-  String userID;
+  String? userID;
+
   DeliveryAddress(
       {this.id,
       this.fullName,
diff --git a/lib/domain/vo/message.dart b/lib/domain/vo/message.dart
index fc86b58..3417058 100644
--- a/lib/domain/vo/message.dart
+++ b/lib/domain/vo/message.dart
@@ -1,15 +1,15 @@
 import 'package:cloud_firestore/cloud_firestore.dart';
 
 class Message {
-  String id;
-  String message;
-  DateTime date;
-  String receiverID;
-  String receiverName;
-  String senderID;
-  String senderName;
-  String messageType;
-  String messageID;
+  String? id;
+  String? message;
+  DateTime? date;
+  String? receiverID;
+  String? receiverName;
+  String? senderID;
+  String? senderName;
+  String? messageType;
+  String? messageID;
 
   Message(
       {this.id,
@@ -21,11 +21,13 @@ class Message {
       this.senderName,
       this.messageType,
       this.messageID});
+
   bool fromToday() {
+    if (date == null) return false;
     var now = DateTime.now();
-    return date.day == now.day &&
-        date.month == now.month &&
-        date.year == now.year;
+    return date!.day == now.day &&
+        date!.month == now.month &&
+        date!.year == now.year;
   }
 
   Map<String, dynamic> toMap() {
@@ -36,9 +38,10 @@ class Message {
   }
 
   bool sameDay(Message another) {
-    return date.year == another.date.year &&
-        date.month == another.date.month &&
-        date.day == another.date.day;
+    if (date == null) return false;
+    return date!.year == another.date!.year &&
+        date!.month == another.date!.month &&
+        date!.day == another.date!.day;
   }
 
   factory Message.fromMap(Map<String, dynamic> map, String id) {
@@ -52,7 +55,7 @@ class Message {
       receiverName: map['receiver_name'],
       messageType: map['msg_type'],
       messageID: map['msg_id'],
-      date: date != null ? date.toDate() : null,
+      date: date.toDate(),
     );
   }
 }
diff --git a/lib/domain/vo/privilege.dart b/lib/domain/vo/privilege.dart
index 5b913b2..85907a2 100644
--- a/lib/domain/vo/privilege.dart
+++ b/lib/domain/vo/privilege.dart
@@ -1,20 +1,24 @@
 import 'package:fcs/domain/constants.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
 class Privilege {
   String id;
-  String name;
-  String desc;
-  bool sysAdminOnly = true;
-  bool isChecked = false;
+  String? name;
+  String? desc;
+  bool? sysAdminOnly = true;
+  bool? isChecked = false;
 
-  IconData iconData;
+  IconData? iconData;
 
   Privilege(
-      {this.id, this.name, this.desc, this.isChecked, this.sysAdminOnly}) {
+      {required this.id,
+      this.name,
+      this.desc,
+      this.isChecked,
+      this.sysAdminOnly}) {
     if (this.id == privilege_admin) {
       iconData = MaterialCommunityIcons.account_tie;
     } else if (this.id == privilege_support) {
diff --git a/lib/domain/vo/radio.dart b/lib/domain/vo/radio.dart
deleted file mode 100644
index ab1a7a1..0000000
--- a/lib/domain/vo/radio.dart
+++ /dev/null
@@ -1,5 +0,0 @@
-class RadioGroup {
-  String text;
-  int index;
-  RadioGroup({this.text, this.index});
-}
\ No newline at end of file
diff --git a/lib/domain/vo/shipment_status.dart b/lib/domain/vo/shipment_status.dart
index ed4549c..7783190 100644
--- a/lib/domain/vo/shipment_status.dart
+++ b/lib/domain/vo/shipment_status.dart
@@ -3,17 +3,21 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 class ShipmentStatus {
   String status;
   DateTime date;
-  bool done;
-  String staffId;
-  String staffName;
+  bool? done;
+  String? staffId;
+  String? staffName;
   ShipmentStatus(
-      {this.status, this.date, this.done, this.staffId, this.staffName});
+      {required this.status,
+      required this.date,
+      this.done,
+      this.staffId,
+      this.staffName});
 
   factory ShipmentStatus.fromMap(Map<String, dynamic> map) {
     var _date = (map['date'] as Timestamp);
     return ShipmentStatus(
         status: map['status'],
-        date: _date == null ? null : _date.toDate(),
+        date: _date.toDate(),
         done: map['done'],
         staffId: map['staff_id'],
         staffName: map['staff_name']);
diff --git a/lib/domain/vo/status.dart b/lib/domain/vo/status.dart
index e229726..a8b5b7b 100644
--- a/lib/domain/vo/status.dart
+++ b/lib/domain/vo/status.dart
@@ -1,8 +1,7 @@
-
 class Status {
-  String status;
-  String message;
-  String errorCode;
+  String? status;
+  String? message;
+  String? errorCode;
   Status(this.status, this.message);
 
   Status.fromJson(Map<String, dynamic> json) {
@@ -10,4 +9,4 @@ class Status {
     message = json['message'];
     errorCode = json['error_code'];
   }
-}
\ No newline at end of file
+}
diff --git a/lib/domain/vo/term.dart b/lib/domain/vo/term.dart
index b9c1086..9aa2c26 100644
--- a/lib/domain/vo/term.dart
+++ b/lib/domain/vo/term.dart
@@ -1,8 +1,8 @@
 import 'package:fcs/domain/entities/setting.dart';
 
 class Term {
-  String termEng;
-  String termMm;
+  String? termEng;
+  String? termMm;
 
   Term({this.termEng, this.termMm});
 
diff --git a/lib/helpers/api_helper.dart b/lib/helpers/api_helper.dart
index 06fca69..8eacdd2 100644
--- a/lib/helpers/api_helper.dart
+++ b/lib/helpers/api_helper.dart
@@ -20,8 +20,8 @@ Future<dynamic> requestAPI(
   String path,
   method, {
   dynamic payload,
-  String token,
-  String url,
+  String? token,
+  String? url,
 }) async {
   DevInfo devInfo = await DevInfo.getDevInfo();
 
@@ -33,7 +33,7 @@ Future<dynamic> requestAPI(
     headers["Token"] = token;
   }
   if (devInfo != null && devInfo.deviceID != null && deviceName != null) {
-    headers["Device"] = devInfo.deviceID + ":" + deviceName;
+    headers["Device"] = devInfo.deviceID??"" + ":" + deviceName;
   }
   headers["Project-ID"] = Config.instance.reportProjectID;
 
@@ -66,7 +66,7 @@ Future<dynamic> requestAPI(
 // request makes http request
 // if token is null
 Future<dynamic> requestDownloadAPI(String path, method,
-    {dynamic payload, String token, String url, String filePath}) async {
+    {dynamic payload, String? token, String? url, String? filePath}) async {
   DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
   AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
   String deviceName = "${androidInfo.model}(${androidInfo.id})";
@@ -81,7 +81,7 @@ Future<dynamic> requestDownloadAPI(String path, method,
     log.info("Path:$baseUrl$path");
     HttpClient client = new HttpClient();
     var _downloadData = StringBuffer();
-    var fileSave = new File(filePath);
+    var fileSave = new File(filePath!);
     var request = await client.getUrl(Uri.parse("$baseUrl$path"));
     request.headers.set("Project-ID", Config.instance.reportProjectID);
     request.headers
@@ -108,7 +108,7 @@ Future<dynamic> requestDownloadAPI(String path, method,
 // request makes http request
 // if token is null
 Future<dynamic> requestDownloadPDFAPI(String path, method,
-    {dynamic payload, String token, String url, String filePath}) async {
+    {dynamic payload, String? token, String? url, String? filePath}) async {
   DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
   AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
   String deviceName = "${androidInfo.model}(${androidInfo.id})";
@@ -123,7 +123,7 @@ Future<dynamic> requestDownloadPDFAPI(String path, method,
     log.info("Path:$baseUrl$path");
     HttpClient client = new HttpClient();
     // var _downloadData = StringBuffer();
-    var fileSave = new File(filePath);
+    var fileSave = new File(filePath!);
     var request = await client.getUrl(Uri.parse("$baseUrl$path"));
     request.headers.set("Project-ID", Config.instance.reportProjectID);
     if (token != null) {
@@ -135,7 +135,7 @@ Future<dynamic> requestDownloadPDFAPI(String path, method,
     request.headers.set("payload", escapePayload);
     var response = await request.close();
     print("headers:${response.headers}");
-    var _downloadData = List<int>();
+    List<int> _downloadData = [];
 
     response.listen((d) => _downloadData.addAll(d), onDone: () {
       fileSave.writeAsBytes(_downloadData);
@@ -155,10 +155,10 @@ typedef OnDownloadDone(File file);
 // if token is null
 Future<dynamic> requestDownload(String path, method,
     {dynamic payload,
-    String token,
-    String url,
-    String filePath,
-    OnDownloadDone onDownloadDone}) async {
+    required String token,
+    required String url,
+    required String filePath,
+    OnDownloadDone? onDownloadDone}) async {
   DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
   AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
   String deviceName = "${androidInfo.model}(${androidInfo.id})";
@@ -188,7 +188,7 @@ Future<dynamic> requestDownload(String path, method,
     // request.write(escapePayload);
     var response = await request.close();
     print("headers:${response.headers}");
-    var _downloadData = List<int>();
+    List<int> _downloadData = [];
     var cd = response.headers.value("content-disposition");
     String fileName = "download.csv";
     if (cd != null && cd.contains("filename=")) {
diff --git a/lib/helpers/dev_info.dart b/lib/helpers/dev_info.dart
index 255bf92..2d2c72d 100644
--- a/lib/helpers/dev_info.dart
+++ b/lib/helpers/dev_info.dart
@@ -2,13 +2,13 @@ import 'package:device_info/device_info.dart';
 import 'dart:io' show Platform;
 
 class DevInfo {
-  bool isAndroid;
-  bool isIOS;
-  String deviceID;
-  String id;
-  String model;
+  bool? isAndroid;
+  bool? isIOS;
+  String? deviceID;
+  String? id;
+  String? model;
 
-  static DevInfo _instance;
+  static DevInfo? _instance;
 
   static Future<DevInfo> getDevInfo() async {
     if (_instance != null) return Future.value(_instance);
@@ -18,14 +18,14 @@ class DevInfo {
 
     if (Platform.isAndroid) {
       AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
-      _instance.deviceID = androidInfo.androidId;
-      _instance.id = androidInfo.id;
-      _instance.model = androidInfo.model;
+      _instance!.deviceID = androidInfo.androidId;
+      _instance!.id = androidInfo.id;
+      _instance!.model = androidInfo.model;
     } else if (Platform.isIOS) {
       IosDeviceInfo iosDeviceInfo = await deviceInfo.iosInfo;
-      _instance.deviceID = iosDeviceInfo.identifierForVendor;
-      _instance.id = iosDeviceInfo.utsname.release;
-      _instance.model = iosDeviceInfo.model;
+      _instance!.deviceID = iosDeviceInfo.identifierForVendor;
+      _instance!.id = iosDeviceInfo.utsname.release;
+      _instance!.model = iosDeviceInfo.model;
     }
     return Future.value(_instance);
   }
diff --git a/lib/helpers/firebase_helper.dart b/lib/helpers/firebase_helper.dart
index f9539e8..0fd5b84 100644
--- a/lib/helpers/firebase_helper.dart
+++ b/lib/helpers/firebase_helper.dart
@@ -1,32 +1,31 @@
 import 'dart:io';
 
-import 'package:fcs/config.dart';
-import 'package:firebase_auth/firebase_auth.dart';
+import 'package:firebase_auth/firebase_auth.dart' as fb;
 import 'package:firebase_storage/firebase_storage.dart';
 import 'package:logging/logging.dart';
 import 'package:uuid/uuid.dart';
 
 final log = Logger('firebaseHelper');
 
-final FirebaseAuth auth = FirebaseAuth.instance;
+final fb.FirebaseAuth auth = fb.FirebaseAuth.instance;
 
 Future<String> getToken() async {
-  FirebaseUser firebaseUser = await auth.currentUser();
-  IdTokenResult token = await firebaseUser.getIdToken();
-  return token.token;
+  fb.User? firebaseUser = fb.FirebaseAuth.instance.currentUser;
+  String token = await firebaseUser?.getIdToken() ?? "";
+  return token;
 }
 
-Future<Map> getClaims({bool refreshIdToken = false}) async {
-  FirebaseUser firebaseUser = await auth.currentUser();
+Future<Map?> getClaims({bool refreshIdToken = false}) async {
+  fb.User? firebaseUser = auth.currentUser;
   if (firebaseUser == null) return null;
-  IdTokenResult idToken =
-      await firebaseUser.getIdToken(refresh: refreshIdToken);
+  fb.IdTokenResult idToken =
+      await firebaseUser.getIdTokenResult(refreshIdToken);
   return idToken.claims;
 }
 
 // returns list of url
 Future<List<String>> uploadFiles(String path, List<File> files,
-    {String fileName}) async {
+    {String? fileName}) async {
   List<Future<String>> fu = [];
   for (File f in files) {
     Future<String> u = uploadStorage(path, f);
@@ -35,22 +34,27 @@ Future<List<String>> uploadFiles(String path, List<File> files,
   return Future.wait(fu);
 }
 
-Future<String> uploadStorage(String path, File file, {String fileName}) async {
+Future<String> uploadStorage(String path, File file, {String? fileName}) async {
   if (fileName == null) {
     fileName = Uuid().v4();
   }
-  StorageReference storageReference =
-      FirebaseStorage(storageBucket: Config.instance.bucketName)
-          .ref()
-          .child('$path/$fileName');
-  StorageUploadTask uploadTask = storageReference.putFile(file);
-  await uploadTask.onComplete;
-  String downloadUrl = await storageReference.getDownloadURL();
-  print("name:${await storageReference.getName()}");
-  print("bucket:${await storageReference.getBucket()}");
-  print("path:${await storageReference.getPath()}");
-  print("meta:${await storageReference.getMetadata()}");
+  Reference ref = FirebaseStorage.instance.ref().child('$path/$fileName');
+  UploadTask uploadTask = ref.putFile(file);
+  await uploadTask.resume();
+  String downloadUrl = await ref.getDownloadURL();
   return downloadUrl;
+  // StorageReference storageReference =
+  //     FirebaseStorage(storageBucket: Config.instance.bucketName)
+  //         .ref()
+  //         .child('$path/$fileName');
+  // StorageUploadTask uploadTask = storageReference.putFile(file);
+  // await uploadTask.onComplete;
+  // String downloadUrl = await storageReference.getDownloadURL();
+  // print("name:${await storageReference.getName()}");
+  // print("bucket:${await storageReference.getBucket()}");
+  // print("path:${await storageReference.getPath()}");
+  // print("meta:${await storageReference.getMetadata()}");
+  // return downloadUrl;
 }
 
 Future<void> deleteStorageFromUrls(List<String> urls) async {
@@ -62,10 +66,12 @@ Future<void> deleteStorageFromUrls(List<String> urls) async {
 
 Future<void> deleteStorageFromUrl(String url) async {
   try {
-    StorageReference storageReference =
-        await FirebaseStorage(storageBucket: Config.instance.bucketName)
-            .getReferenceFromUrl(url);
-    await storageReference.delete();
+    Reference ref = FirebaseStorage.instance.refFromURL(url);
+    await ref.delete();
+    // StorageReference storageReference =
+    //     await FirebaseStorage(storageBucket: Config.instance.bucketName)
+    //         .getReferenceFromUrl(url);
+    // await storageReference.delete();
   } catch (e) {
     log.warning("deleteStorage:$e");
   }
diff --git a/lib/helpers/network_connectivity.dart b/lib/helpers/network_connectivity.dart
index fe7c21d..4a7932d 100644
--- a/lib/helpers/network_connectivity.dart
+++ b/lib/helpers/network_connectivity.dart
@@ -11,7 +11,7 @@ class NetworkConnectivity {
   final log = Logger('NetworkConnectivity');
 
   static final NetworkConnectivity instance = NetworkConnectivity._internal();
-  static String hostName;
+  static String? hostName;
   NetworkConnectivity._internal() {
     _initialise();
     var uri = Uri.parse(Config.instance.apiURL);
@@ -38,7 +38,7 @@ class NetworkConnectivity {
     // lookup if connectivity is not none
     if (result != ConnectivityResult.none) {
       try {
-        final hostNameLookup = await InternetAddress.lookup(hostName);
+        final hostNameLookup = await InternetAddress.lookup(hostName ?? "");
         if (hostNameLookup.isNotEmpty &&
             hostNameLookup[0].rawAddress.isNotEmpty) {
           if (await checkHeartbeat()) {
diff --git a/lib/helpers/paginator.dart b/lib/helpers/paginator.dart
index cb89f15..240a8e3 100644
--- a/lib/helpers/paginator.dart
+++ b/lib/helpers/paginator.dart
@@ -13,7 +13,7 @@ class Paginator<T> {
   final log = Logger('Paginator');
 
   final int rowPerLoad;
-  DocumentSnapshot prev;
+  DocumentSnapshot? prev;
   bool ended = false;
   bool isLoading = false;
   List<T> values = [];
@@ -21,7 +21,7 @@ class Paginator<T> {
 
   Query pageQuery;
 
-  Paginator(this.pageQuery, {this.rowPerLoad = 20, this.toObj}) {
+  Paginator(this.pageQuery, {this.rowPerLoad = 20, required this.toObj}) {
     _clearState();
   }
 
@@ -36,27 +36,27 @@ class Paginator<T> {
     _clearState();
   }
 
-  Future<void> refresh({CallBack onFinished}) async {
+  Future<void> refresh({CallBack? onFinished}) async {
     _clearState();
     await load();
     if (onFinished != null) onFinished();
   }
 
-  Future<bool> load({CallBack onFinished}) async {
+  Future<bool?> load({CallBack? onFinished}) async {
     if (ended) return null;
     isLoading = true;
     Query _query =
-        prev != null ? pageQuery.startAfterDocument(prev) : pageQuery;
+        prev != null ? pageQuery.startAfterDocument(prev!) : pageQuery;
     try {
       await _query
           .limit(rowPerLoad)
-          .getDocuments(source: Source.server)
+          .get(GetOptions(source: Source.server))
           .then((QuerySnapshot snapshot) {
-        int count = snapshot.documents.length;
+        int count = snapshot.docs.length;
         ended = count < rowPerLoad;
-        prev = count > 0 ? snapshot.documents[count - 1] : prev;
-        snapshot.documents.forEach((e) {
-          values.add(toObj(e.data, e.documentID));
+        prev = count > 0 ? snapshot.docs[count - 1] : prev;
+        snapshot.docs.forEach((e) {
+          values.add(toObj(e.data() as Map<String, dynamic>, e.id));
         });
       });
     } catch (e) {
diff --git a/lib/helpers/shared_pref.dart b/lib/helpers/shared_pref.dart
index d2f26f8..e020232 100644
--- a/lib/helpers/shared_pref.dart
+++ b/lib/helpers/shared_pref.dart
@@ -7,17 +7,17 @@ class SharedPref {
   static final SharedPref instance = SharedPref._();
   SharedPref._();
 
-  static Future<bool> isFirstLaunch() async {
+  static Future<bool?> isFirstLaunch() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
     return prefs.getBool('first_launch');
   }
 
   static Future<void> finishFirstLaunch() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
-    return prefs.setBool('first_launch', false);
+    prefs.setBool('first_launch', false);
   }
 
-  static Future<String> getLang() async {
+  static Future<String?> getLang() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
     return prefs.getString('language');
   }
@@ -27,7 +27,7 @@ class SharedPref {
     prefs.setString('language', lang);
   }
 
-  static Future<bool> getStaffMode() async {
+  static Future<bool?> getStaffMode() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
     return prefs.getBool('staff_mode_on');
   }
@@ -41,7 +41,7 @@ class SharedPref {
     await _save("user", user.toJson());
   }
 
-  static Future<User> getUser() async {
+  static Future<User?> getUser() async {
     try {
       return User.fromJson(await _read("user"));
     } catch (e) {
@@ -57,7 +57,7 @@ class SharedPref {
     await _save("skipped_recovery_email", skipped);
   }
 
-  static Future<bool> getSkippedRecoverEmail() async {
+  static Future<bool?> getSkippedRecoverEmail() async {
     try {
       bool _skipped = await _read("skipped_recovery_email");
       return _skipped;
@@ -69,7 +69,7 @@ class SharedPref {
   static _read(String key) async {
     try {
       final prefs = await SharedPreferences.getInstance();
-      return json.decode(prefs.getString(key));
+      return json.decode(prefs.getString(key) ?? "");
     } catch (e) {
       print("Error:$e");
     }
diff --git a/lib/helpers/theme.dart b/lib/helpers/theme.dart
index e029208..e3ec100 100644
--- a/lib/helpers/theme.dart
+++ b/lib/helpers/theme.dart
@@ -20,8 +20,10 @@ const TextStyle labelStyleMM = TextStyle(
     fontFamily: "Myanmar3");
 const TextStyle subMenuStyle =
     TextStyle(fontSize: 14, color: Colors.white, fontWeight: FontWeight.w500);
-const TextStyle subMenuStyleMM =
-    TextStyle(fontSize: 14, color: Colors.white, fontWeight: FontWeight.w500,
+const TextStyle subMenuStyleMM = TextStyle(
+    fontSize: 14,
+    color: Colors.white,
+    fontWeight: FontWeight.w500,
     fontFamily: "Myanmar3");
 
 const TextStyle welcomeLabelStyle =
@@ -31,11 +33,10 @@ const TextStyle welcomeSubLabelStyle =
 const TextStyle siginButtonStyle =
     TextStyle(fontSize: 16, color: Colors.white, fontWeight: FontWeight.w500);
 
-
 TextStyle newLabelStyle(
-    {Color color,
-    double fontSize,
-    FontWeight fontWeight,
+    {Color? color,
+    double? fontSize,
+    FontWeight? fontWeight,
     bool underline = false}) {
   return TextStyle(
       fontSize: fontSize == null ? 14 : fontSize,
@@ -45,9 +46,9 @@ TextStyle newLabelStyle(
 }
 
 TextStyle newLabelStyleMM(
-    {Color color,
-    double fontSize,
-    FontWeight fontWeight,
+    {Color? color,
+    double? fontSize,
+    FontWeight? fontWeight,
     bool underline = false}) {
   return TextStyle(
       fontSize: fontSize == null ? 13 : fontSize,
@@ -59,8 +60,8 @@ TextStyle newLabelStyleMM(
 
 const TextStyle photoLabelStyle =
     TextStyle(color: Colors.black, fontSize: 13.0);
-const TextStyle photoLabelStyleMM = TextStyle(
-    color: Colors.black, fontSize: 13.0, fontFamily: "Myanmar3");
+const TextStyle photoLabelStyleMM =
+    TextStyle(color: Colors.black, fontSize: 13.0, fontFamily: "Myanmar3");
 const TextStyle textStyle =
     TextStyle(fontSize: 14, color: Colors.black87, fontWeight: FontWeight.w500);
 const TextStyle textStyleOdd = TextStyle(
diff --git a/pubspec.yaml b/pubspec.yaml
index 6d589fb..89b0fa2 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -43,7 +43,7 @@ dependencies:
   permission_handler: ^8.1.4+2
   country_code_picker: ^2.0.2
   pin_input_text_field: ^4.1.0
-  # flutter_icons: ^1.1.0
+  flutter_icons_null_safety: ^1.1.0
   country_icons: ^2.0.2
   timeline_list: ^0.0.5
   # barcode_scan: ^2.0.2