Is it possible to enable Firebase email authentication but disable sign in?

Question

In my app, I\'m already using the Firebase authentication with Google accounts, but I\'d also like to authorize some users who have no Google account. So I\'d like to manually a

Answer 1

I'm using passwordless Firebase Authentication and I hacked my way around this by using a callable cloud function that's triggered from my login form. The cloud function looks up the submitted email address in a whitelist firebase node and returns true or false. If true, do sign in. If false, I flash a "we're in closed beta" message.

I add emails to the whitelist node both manually and from a form within a protected admin route in my app.