You published the .yyp file, not a native executable. You should be able to export your game to different operating systems from the GameMaker editor.
How do I do that this is my first jam and first time using itch.io
I haven't used GM2 but I found this tutorial for you:
hey, I use gamemaker and I can walk you through this if you want
https://discord.gg/SEjng6Hb
if you join here I'll try help anyway I can
