title: No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()) although Firebase is being initialized
body: <p>I have a firebase_service.dart file when I create references to all my services. The code for that is here</p>
  <pre><code>import 'package:cloud_firestore/cloud_firestore.dart';
  import 'package:firebase_auth/firebase_auth.dart';
  import 'package:firebase_storage/firebase_storage.dart';
  
  class FirebaseService {
    FirebaseAuth _auth = FirebaseAuth.instance;
    FirebaseStorage _storage = FirebaseStorage.instance;
    FirebaseFirestore _db = FirebaseFirestore.instance;
    FirebaseService();
  }
  </code></pre>
  <p>However I receive this error - <em>Exception has occurred.
  FirebaseException ([core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp())</em></p>
  <p>In my main.dart file I have initialized firebase as seen below</p>
  <pre><code>void main() async {
    WidgetsFlutterBinding.ensureInitialized(); //Ensures app is initialized first
    await Firebase.initializeApp; 
    GetIt.instance.registerSingleton&lt;FirebaseService&gt;(
      FirebaseService(),
    );
    runApp(const MyApp());
  }
  </code></pre>
  <p>However I am seeing a squiggly line under the await keyword and this is the comment - <em>'await' applied to 'Future Function({String? name, FirebaseOptions? options})', which is not a 'Future'</em></p>
  <p>Could that be the issue? I am not so sure what is wrong here</p>