Configuring custom private repo of discourse through docker

I was able to disable it with

Even though I am not using the SSO functionality discourse provides as I don’t think I can with roblox? Roblox does not provide a email for the user.

I guess is it even possible for me to do this and not have users change their name,username,avatar while at the same time roblox not providing a email? Since I know when I log in with OAuth it fills in the username, name, and avatar, but I don’t want them to be able to change the username, and name on sign-up. but atleast let them provide a email