User handles / usernames
I would like every user of my app to have a (unique) username, similar to handles on e.g. Twitter, Instragram, reddit... It's a bit unclear how to do this though. I've enabled username sign-in, so users can sign in and sign up using a username. However, it's still possible for a user to sign up with just an e-mail address. How do I force every user to pick a (unique) username? Or would you recommend I only keep e-mails in Kinde and keep usernames separate in my own DB?
