Flutter and Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app) - firebase

Question

I've set up firebase with Flutter for iOS and Android.
When running flutter run I'm getting the error with the following error:
FirebaseError: Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp()
(app/no-app).
at Object.f [as app] (https://www.gstatic.com/firebasejs/7.20.0/firebase-app.js:1:17054)
at Object.app$ [as app]
(http://localhost:50861/packages/firebase_core_web/src/interop/core.dart.lib.js:42:101)
at initializeApp
(http://localhost:50861/packages/firebase_core_web/firebase_core_web.dart.lib.js:101:25)
at initializeApp.next (<anonymous>)
at runBody (http://localhost:50861/dart_sdk.js:39052:34)
at Object._async [as async] (http://localhost:50861/dart_sdk.js:39083:7)
at firebase_core_web.FirebaseCoreWeb.new.initializeApp
(http://localhost:50861/packages/firebase_core_web/firebase_core_web.dart.lib.js:94:20)
at initializeApp (http://localhost:50861/packages/firebase_core/firebase_core.dart.lib.js:117:59)
at initializeApp.next (<anonymous>)
at runBody (http://localhost:50861/dart_sdk.js:39052:34)
at Object._async [as async] (http://localhost:50861/dart_sdk.js:39083:7)
at Function.initializeApp
(http://localhost:50861/packages/firebase_core/firebase_core.dart.lib.js:116:20)
at main$ (http://localhost:50861/packages/scbeta/main.dart.lib.js:477:36)
at main$.next (<anonymous>)
at runBody (http://localhost:50861/dart_sdk.js:39052:34)
at Object._async [as async] (http://localhost:50861/dart_sdk.js:39083:7)
at main$ (http://localhost:50861/packages/scbeta/main.dart.lib.js:475:18)
at main (http://localhost:50861/web_entrypoint.dart.lib.js:49:29)
at main.next (<anonymous>)
at http://localhost:50861/dart_sdk.js:39032:33
at _RootZone.runUnary (http://localhost:50861/dart_sdk.js:38889:58)
at _FutureListener.thenAwait.handleValue (http://localhost:50861/dart_sdk.js:33875:29)
at handleValueCallback (http://localhost:50861/dart_sdk.js:34435:49)
at Function._propagateToListeners (http://localhost:50861/dart_sdk.js:34473:17)
at _Future.new.[_completeWithValue] (http://localhost:50861/dart_sdk.js:34315:23)
at http://localhost:50861/dart_sdk.js:33526:46
at _RootZone.runUnary (http://localhost:50861/dart_sdk.js:38889:58)
at _FutureListener.then.handleValue (http://localhost:50861/dart_sdk.js:33875:29)
at handleValueCallback (http://localhost:50861/dart_sdk.js:34435:49)
at Function._propagateToListeners (http://localhost:50861/dart_sdk.js:34473:17)
at _Future.new.[_completeWithValue] (http://localhost:50861/dart_sdk.js:34315:23)
at async._AsyncCallbackEntry.new.callback (http://localhost:50861/dart_sdk.js:34338:35)
at Object._microtaskLoop (http://localhost:50861/dart_sdk.js:39176:13)
at _startMicrotaskLoop (http://localhost:50861/dart_sdk.js:39182:13)
at http://localhost:50861/dart_sdk.js:34689:9
The main function in my main.dart looks like this:
Future<void> main() async {
// Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
I haven't made any firebase calls or initialisations anywhere else in the app.
In my pubspec.yaml I only have firebase_core: ^1.0.1 as a dependency
I have looked at several questions on StackOverflow of people who've had similar problems but none of the solutions where of any help to me.

Answer 1

Have you already created firebase app and configure it for your flutter app?

Answer 2

I've solved it.
The problem was, that with Flutter 2 which just came out a few days ago, you have to add web as a platform as well which none of the tutorials or solutions I've seen mentioned. Once I've added Web on firebase and the scripts in flutter it worked just fine.