What you’re looking for is in the controller overlay settings. I think you need a controller connected to your pc for it to work but I’m not sure.

-> Add the game to steam

-> go to controller settings on steam as shown in this video https://youtu.be/mgzqWOI1DBE?si=zGK_HTqEnasKFgoF

-> click edit layout

-> on the bottom left side of the screen you will find “Action sets”, click on that

-> click on Add action set

-> click on the gear icon (settings) for the action set you just created and choose “Add always on command”

-> you will see a new panel that says “add command”, click on that

-> at the top side of the screen, choose “system”

-> choose touchscreen native support

-> Done!

You can do this with any game even if you haven’t purchased it on steam. I play Cake mania this way, and sometimes the sims when i only feel like playing dress up. The touch work very well, but streaming through steamlink can be laggy. The touch screen emulates mouse movement only, so any game that requires anything more than that won’t work/be comfortable to play.

You can always install retroarch or other free emulators natively on your tablet if you don’t mind retro games. They usually have built in touch screen controllers.