I want make login function

reference: kenjis page
https://zenn.dev/kenjis/articles/95f38b7e447155

I am trying to create a login function. It worked fine up to the point where I got the login screen, but I don't seem to receive the email.

You probably need to set gmail smtp, but where should I refer?

https://drive.google.com/file/d/1ZYV1DNW...p=drivesdk