Plex Beta app installed on Xbox One, but requires invite?
On Xbox, there are two Plex apps listed in the store. There's the normal Plex app for Xbox (which hasn't been updated in a long time, but works), and there's a Plex Beta app. This beta app looks like it includes the new UI and features, and is a UWP app so it'd support new APIs for background playback, bitstream audio, overlay/PiP (if Plex implements these things, of course).
I'm on an Xbox One (original 2013 model), Xbox Insider Alpha (Windows 10 build 16257.1002, fall creators update preview).
I can install the app, but launching it tells me it's an invite-only beta, and that I must register for it on the Plex forums. I don't see anything about joining the beta here, so where can I register for it? Does it require Plex Pass? If the updated app is available, I would consider subscribing.