Libation: Download DRM Free copies of those audiobooks you've paid for on Audible.
The project has versions for Windows, Linux and macOS, and even ARM builds for those using M Series macs and ARM on Linux.
Link here: https://github.com/rmcrackan/Libation
Oh yeah, it'll work fine on any truenas/unraid/synology system it works on about anything with docker/linux there's even a beta for windows.
My only complaint is a lack of URLbase so setting up a reverse proxy on some setups does not work well.