http://lbrdtjaj7567ptdd4rv74lv27qhxfkraabnyphgcvptl64ijx2tijwid.onion
As for the technical aspects, below I use libraries like yt-dlp, an unofficial library for the YouTube API, and the official library for the Spotify API. That's why, to use SpotifySaver, you'll need Spotify API credentials (you can log in from the developer page; it's not very complicated, don't worry).