How can I send OTP Code to both email and Phone number using firebase at the time of user registration and Sign IN

Question

I am developing an social media and I want to implement a passwordless signup process using only OTP, Also I want to know what should be validation for both phone and email address at the time! Please Help

Answer 1

This is not possible. Firebase Auth provides the ability to sign in with a phone number and the ability to sign in with email link. Those are separate providers. You can trigger them at the same time but they will result with 2 accounts created. Unless, you start with one and then link the other. For example you can sign up with email link and then add a phone number to the account created. Afterwards the user can sign in with either mechanism.