Verify user email

I have successfully created a simple login/signup page where a user can login to their account with their email address & password, or create an account with their email address and create a password. The email and password is saved in firebase. How can I send a verification to their email? Basically, is there any way with fire base I could make sure they only create accounts with email addresses that they own? I just don’t want users to create hundreds of accounts .

On a side question, would creating user accounts allow me to save their progress or amount of coins in web only? Like without mobiles, would I be able to save an users amount of coins somehow? (I just want to make sure this is possible but don’t need an in detail explanation for this)

Hello @ap31
I never use it, but I find this service: Our new free email verification service [with API]