Log in by Firebase

Hello Everybody!
I use Realtime Datebase in Firebase. I made sign up system and it works, because I can see login and password in Firebase Sheet. How can I make login system? It means to read and check text in both boxes and go to next screen if correct or if incorrect to show that data is incorrect.



Hello Everybody!
I am looking for blocks "ready to use" for firebase to login and signup system.

I have given you two examples already, what is not to like ?