The phone number and SMS code here must have been configured in the Firebase Console (Authentication > Sign In Method > Phone).

Once this has been called, every call to PhoneAuthProvider#verifyPhoneNumber() with the same phone number as the one that is configured here will have onVerificationCompleted() triggered as the callback.

Calling this method a second time will overwrite the previously passed parameters. Only one number can be configured at a given time.

Calling this method with either parameter set to null removes this functionality until valid parameters are passed.

Verifying a phone number other than the one configured here will trigger normal behaviour. If the phone number is configured as a test phone number in the console, the regular testing flow occurs. Otherwise, normal phone number verification will take place.

When this is set and PhoneAuthProvider#verifyPhoneNumber() is called with a matching phone number, onCodeAutoRetrievalTimeOut(String) will never be called.