I'm not sure how to use joiplay
-press the plus button
-Enter the game file into the 'executable file' column, in the game folder there is a file in .exe format
-Enter a name and image to make it easier for you
There is a possibility of experiencing lag and some bug, because you are forced to play it on Android
Joiplay cannot run games made with the unity engine
If you are still confused, there are many guides on the internet, try it