I am trying to gain access to gmail in my flutter app. However I cannot even go past the permission screen because of this invalid_client issue. I have already created the oauth 2.0 clientid in my Google Cloud and set the type to android. When I try to use the link I am given, I get this screen.

Error Screen

this is my code;

final clientId = ClientId('99899xxxxxxxx.apps.googleusercontent.com');

class GoogleService{
  Future<void> authenticateAndFetchEmails() async {
    final scopes = ['https://www.googleapis.com/auth/gmail.readonly'];

    await clientViaUserConsent(clientId, scopes, (uri) {
      // Open the URL in a web browser for user consent
      print('Please visit the following URL and authorize the app: $uri');
    }).then((AuthClient client) async {
      final gmailApi = gmail.GmailApi(client);
      final response = await gmailApi.users.messages.list('me');
      final messages = response.messages ?? [];

      for (var message in messages) {
        final msg = await gmailApi.users.messages.get('me', message.id!);
        final snippet = msg.snippet!;

        if (snippet.contains('Debit') ||
            snippet.contains('Account Name') ||
            snippet.contains('Description')) {
          print('Found email: ${msg.payload!.headers!.firstWhere((header) => header.name == 'Subject').value}');
        }
      }
    }).catchError((e) {
      print('Failed to authenticate or fetch emails: $e');
    });
  }
}

I have checked and crosschecked, my clientId is correct. what could be the issue

In the OAuth consent screen, I have added the relevant email as a part of the test users, I have used the client id given to me in the client_secret.json file as well as the clientId in the credential screen. Neither seem to work. I just created the clientId yesterday, so it cannot be invalid or expired. At this point, I need some help