You could signup for MetaHuman with just an email address; you did not have to be logged in to request an invite. I received an early access invite today. The first step asks you to login. Well, I didn’t have an unreal engine account when I received the MetaHuman invite so I created one and then nothing happened. I visited the early access invite link again.
I then clicked on the button, “Launch the App” and am presented with a page that says: