I completed the form and got the hint, but it just doesn't work, as if there was no join button... :/ Where I click just do the usual thing a click do (can't say more as it's a secret >.<)
I am on a computer and in fullscreen, using Firefox.
Just checked and the button is working as it should, so i sent you an email with what I'm pretty sure seems to be the problem. Let me know if that fixes it or if you need help with anything else!