To get to a closed torrent tracker or another closed site, you need to receive an invite (invitation), which is actually a link or an invite code, which is sent to your mail and allows you to register your account on the desired site. After registering on the tracker, you get access to the internal database of torrents and you can download for yourself almost any information that cannot be found or downloaded in the public domain. A closed torrent tracker differs from free access sites in that it is the uniqueness and high quality of material that is often created and downloaded by well-known release groups, as well as good seeding of torrents and high upload speeds. Often this applies to music, feature films and documentaries, TV programs and other content, the quality of which has recently been imposed great demands, given the relevance and popularity of "heavy" data formats, such as lossless for music or Blu-Ray for video. For example, I use the services https://invitez.net/, and which service do you use?