The Pirate Bay (TPB), one of the most infamous site for torrents, has switched to a new v3 onion domain on the Dark Web. The only official backup address for TPB is its .onion domain, which it has had for years.
SuprBay is the official forum of The Pirate Bay. You can get help here for all of the Bay sites. Members use these forums as a way to communicate with others that have an interest in file sharing as well as to join in discussions.