You're honestly better off to buy a proper box that has proper options like a buzz or a Formuler z7+ as your Apple TV won't let you record to an external device and you will be severely limited in your recording options even IF you find a software package that works.

Should have mention, I’m using iPlayTV and love it. Only thing missing is recording like GSE has.

Try iplatyv but not sure it has recording functionality.

I use Plex, along with Telly ( https://github.com/tombowditch/telly ) to record. Works well :)