Is the purchased game required on steam?

I'd like to clarify. Does the game have to be bought on steam? It's just that I have a game - a repack from R.G. Mechanics, license, downloaded by torrent (not purchased in steam). When the application starts, it takes a very long authorization, and if it loads, it gives out that you need to bind the account to steam. I ask you to understand correctly and help (I count on help not only from technical support, but also from developers and players).

For now you need to own the game on steam to be able to play faf

This is all very sad.

Its very cheap !!! This game deserves all the better efforts.
https://steamdb.info/app/9350/