Steam can't find games to backup?

I want to backup a steam game and copy it from my laptop to my pc. But I can't backup a single game of mine on my laptop. Steam doesn't even recognize the games for backup. What can I do to make Steam find the game?

Because of the Coran crisis, more and more people are at home and playing on the PC. Because the Steam servers are not designed for so many people, they have restricted a few things. Sover I read it.

I can do this on the PC and it has absolutely nothing to do with the servers🤔

I can do this from my pc to the laptop but not from my laptop to my pc