Flutter MultiProvider Not found - flutter

Question

Error: Could not find the correct Provider above this AuthenticationWrapper Widget
This happens because you used a BuildContext that does not include the provider
of your choice. There are a few common scenarios:
You added a new provider in your main.dart and performed a hot-reload.
To fix, perform a hot-restart.
The provider you are trying to read is in a different route.
Providers are "scoped". So if you insert of provider inside a route, then
other routes will not be able to access that provider.
You used a BuildContext that is an ancestor of the provider you are trying to read.
Make sure that AuthenticationWrapper is under your MultiProvider/Provider.
This usually happens when you are creating a provider and trying to read it immediately
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:park_app/app_styles.dart';
import 'package:provider/provider.dart';
import 'package:shared_preferences/shared_preferences.dart';
import './views/pages.dart';
import 'views/authentication/authentication_service.dart';
import 'Home_Page.dart';
bool? seenOnboard;
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
// to show status bar
SystemChrome.setEnabledSystemUIOverlays(
[SystemUiOverlay.bottom, SystemUiOverlay.top]);
// to load onboard for the first time only
SharedPreferences pref = await SharedPreferences.getInstance();
seenOnboard = pref.getBool('seenOnboard') ?? false; //if null set to false
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
Provider<AuthenticationService>(
create: (_) => AuthenticationService(FirebaseAuth.instance),
),
StreamProvider(
initialData: null,
create: (context) =>
context.read<AuthenticationService>().authStateChanges),
],
child: MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Park App',
theme: ThemeData(
textTheme: GoogleFonts.manropeTextTheme(
Theme.of(context).textTheme,
),
primarySwatch: Colors.blue,
scaffoldBackgroundColor: kScaffoldBackground,
),
home: seenOnboard == true ? AuthenticationWrapper() : OnBoardingPage(),
),
);
}
}
class AuthenticationWrapper extends StatelessWidget {
#override
Widget build(BuildContext context) {
final firebaseUser = context.watch<User>();
if (firebaseUser != null) {
return HomePage();
}
return LoginPage();
}
}

Answer 1

install provider by running the command below:
flutter pub add provider and then in your main.dart file, import it import 'package:provider/provider.dart';

Answer 2

Make sure to specify the generic type on StreamProvider:
StreamProvider<User?>(
...
)
Note that you have set null as initialData, so your widget likely needs to handle null users. Meaning you need to do:
final user = context.watch<User?>()