On my andoird app to do Automatic SMS Verification I can use this:
"Automatic SMS Verification with the SMS Retriever API"
https://developers.google.com/identity/sms-retriever/overview
Nice.
But to do Automatic SMS Verification I can also use Firebase:
"Authenticate with Firebase on Android using a Phone Number"
https://firebase.google.com/docs/auth/android/phone-auth
What is difference between this two approaches?