Not to be pedantic, but that linked thread states:
"This thread is only to provide help on how to download the Tech Test on PlayStation."
Not for questions about the forums. But yes, there are also multiple threads about the forum. Either way:
https://account.theshow.com/techtest/info
"A private forum will be available for those who were selected to participate. The private forum will open shortly before the test servers go live on 2/22."