Apologies if it’s rude to comment here, I am not familar with your discourse expectations. It took me 20 minutes and two browsers to be able to log in here with my preferred email, and wanted to share the pain a bit.
My result was that I got redirected to a login page which offered google and github (which both works, to reference your comment above, so it was really smart to enable them, but they’re using a different email I wanted to use), and asked for email and password below them. As later it turned out this “email” uses some LDAP, which is very secret, since there is no signup link and there is no link where this particular ldap should be found, or info about it. So it kept failing, for obvious reasons. No, there wasn’t plain email button since it would be created by the external script (jquery from some external cdn I guess).
But then I was able to see the hidden prompt on chrome and I was able to actually login with my email (which surprisingly worked), but I do not have a password (and button isn’t present in firefox anyway), since it’s a one-time-only login, as it seems.
The inherent problem is that “FAQ” is actually a ToS, and doesn’t really cover much abolut login, auth systems, and/or problems with them, including bugzilla accounts, mozillians accounts, discourse accounts, ldap account, sync accounts, or god knows what accounts I have lying around which all mozilla something. I’ve been around for a few decades but surprisingly this mess was able to confuse even me.
It would be nice if there was a FAQ about login (since FAQ is readable without registration). Listing the methods (so people may notice if seome of them is missing). Describing the methods, or dismissing confusion with other accounts, or actually telling that yes, this account is the same as the other account. And some explanation about how to register, or what methods doesn’t provide it at all.