Apple TvOS Tablo beta app

do you sign up through The TestFlight app to begin beta testing?

You’ll need to sign up to be a firmware beta tester first:

how exactly do I sign up for the Tablo firmware beta tester

Am I still signed up or do I need to sign up again? The Tablo Blog mentioned a new feature but no date.

Recently purchase an Apple TV 4K and would like to be a beta tester…