Before you start hammering Torrentgalaxy with API requests (even via Jackett), consider the following:
The "API" often refers to one of several ways to access TGx data programmatically: Ryuk-me/Torrents-Api - GitHub Torrentgalaxy Api -
is a public torrent indexer (similar to RARBG, 1337x, The Pirate Bay). The TorrentGalaxy API is not an official, documented REST API like you’d find with legit services. Instead, it refers to: Before you start hammering Torrentgalaxy with API requests