User authentication using firebase

Maybe this can help you :

1. Firebase Authentication in App Inventor Using Javascript

2. App Inventor Tutorials and Examples: User Identification | Pura Vida Apps

3. Topic
https://community.thunkable.com/t/free-firebase-authentication-v-3-0-update-link/8543

4. Topic

5. Topic

6. Topic Free Extension
https://community.appybuilder.com/t/firebase-authentication-extensions/507