Firebase Authentication Error: SMS Verification Fails with Code 17006 - "This operation is not allowed"

[UmerAbbasi1515]

I am encountering an issue when attempting to perform phone number authentication using Firebase Auth in my Flutter application.

The SMS verification request fails with the following error:
SMS verification code request failed: unknown status code: 17006 null
D/FirebaseAuth: Invoking original failure callbacks after phone verification failure for UAE number, error - This operation is not allowed. This may be because the given sign-in provider is disabled for this Firebase project. Enable it in the Firebase console, under the sign-in method tab of the Auth section.
[firebase_auth/operation-not-allowed] This operation is not allowed. This may be because the given sign-in provider is disabled for this Firebase project. Enable it in the Firebase console, under the sign-in method tab of the Auth section.

Steps I’ve already taken:
1- I've verified that phone authentication is enabled in the Firebase console under the Authentication > Sign-in method tab.
2- I ensured that the Firebase project is properly linked with the Flutter app and the correct dependencies (firebase_auth: ^4.1.0, firebase_core: ^2.15.0) are installed and also iOS application working fine.
3- I have checked for any errors in the Firebase configuration or setup within the app, but everything seems correct.
4- I also "Start with 'Allow' to limit SMS usage to selected regions" under Authentication -> Settings tab in firebase console.

Has anyone else encountered this issue or know how to resolve it? Any insights on what might be causing the "This operation is not allowed" error, or what additional steps I might be missing would be greatly appreciated.