premium without google

Please integrate a function, that I can use tv series premium app without google.

How?
Sell the tv series premium app alone as a new app in the playstore.
Or connect the paid premium key to the fema account, that fema servers check the paid key and not google.
Or maybe integrate a paid "code" into the app, which can be verified by fema servers.

Why?
Because of privacy concerns I want to remove all google services from my device, that means the playstore and play services too.
Because of that, the app can't verify the paid fema unlock key, which means that l can't use my paid tv series premium app.?

Of course, l would pay a second time, if I can use tv series premium without google.