Missing or malformed value for Region in awsS3StoragePluginconfiguration. (Flutter, android)

I got this error when I'am trying to configure Amplify:

    try {
    final authPlugin = AmplifyAuthCognito();
    final storage = AmplifyStorageS3();
    await Amplify.addPlugins([authPlugin,storage]);
    await Amplify.configure(amplifyconfig);
   } on Exception catch (e) {
      safePrint('An error occurred configuring Amplify: $e');
    }

In my amplifyconfiguration.dart I have "Region": "us-east-1" everywhere and the same region in my bucket in console. What can I do wrong?