[Unhandled promise rejection: FirebaseError: Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app).] react native code example

Example: [core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp() flutter

import 'package:firebase_core/firebase_core.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}