Interesting one there......log-in screen but no option to sign up??? Yeah, that's useful.......oh wait, it's some kind of puzzle or something????
You either need to get an invite from a member or they would need to interview you.
Seems to me almost like joining a secret clan or something. Too tedious for me. But maybe there's holy heaven in there, I don't know. Guess I won't bother to find out. https://www.whatinterviewprep.com/prepare-for-the-interview/ .