Firebase messaging not working [not receiving notfications] but app connected to firebase

[kavyabhargava]

I was following a tutorial for Firebase push notifications. I followed all the steps: Connecting app to Firebase, and importing packages (Firebase messaging and Firebase push notifications). I tried sending several notifications, but it did not work.

I know my app is connected to Firebase as I am receiving data from Cloud Firestore. Authentication also works and I am also able to write data to storage:

My main.dart:

void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp(
// Added actual values
options: const FirebaseOptions(
apiKey: "have added this ",
appId: "have added this",
messagingSenderId: "have added this",
projectId: "have added this",
storageBucket: "have added this",
),
);
runApp(const MyApp());
}

class MyApp extends StatefulWidget {
const MyApp({Key? key}) : super(key: key);

@OverRide
State createState() => _MyAppState();
}

class _MyAppState extends State {
@OverRide
void initState() {
super.initState();

FirebaseMessaging.instance
.getInitialMessage(); /this helps code below work great

FirebaseMessaging.onMessage.listen((message) {
if (message.notification != null) {
print(message.notification!.body);
print(message.notification!.title);
}
});
FirebaseMessaging.onMessageOpenedApp.listen((message) {

final routeFromMessage = message.data['route'];

print(routeFromMessage);
});
}

@OverRide
Widget build(BuildContext context) {
return ChangeNotifierProvider(
create: (context) => GoogleSignInProvider(),
child: OverlaySupport(
child: MaterialApp(
title: 'News_App_admin',
theme: ThemeData(
buttonTheme: const ButtonThemeData(minWidth: 80),
primarySwatch: Colors.blue,
secondaryHeaderColor: const Color.fromARGB(255, 75, 177, 78),
),
home: // MyHomePage(title: 'Home page'),
StreamBuilder(
builder: (ctx, userSnapshot) {
if (userSnapshot.hasError) {
Center(
child: Text('Unknown Error'),
);
}
if (userSnapshot.hasData) {

          return bottomNavigationBar();
        }
        return const Auth_Screen();
      },
      stream: FirebaseAuth.instance.authStateChanges(),
    ) 

}
}