Why is FirebaseUser not found?

The Firebase user object represents a user account that has signed up for an app in your project . Apps usually have many registered users, and every app in a project shares a user database.

You create a new user in your Firebase project by calling the createUserWithEmailAndPassword method or by signing in a user for the first time using a federated identity provider, such as Google Sign-In or Facebook Login.

To Solve Undefined class ‘FirebaseUser’ just use User instead of FirebaseUser because after the new update of package firebase_auth, the class FirebaseUser was changed to User , and the class AuthResult was changed to UserCredentail. Therefore change FirebaseUser to User.

All other Firebase Auth features are no-cost on all plans . Prices are per successful verification. On the Blaze plan, Phone Authentication provides a no-cost tier. The first 10K verifications for both instances (USA, Canada, and India and All other countries) are provided at no cost each month.