Get a usenet provider. There are many to choose from and there are comparison sites out there. I use cheapness because it gives me a second limited connection to another provider, this helps to make sure everything I want is available by using two possible sources.
Get a nzb indexer, there are some that are preset in rather sonarr and radar screens. Some of them have paid plans that let you do more searches per day.
Configure your arr programs just like you did with torrents.
The catch is its time consuming since it doesn’t support Playlist. There are similar tools that also support up to 100nsong Playlist.