Thanks for the reply😊.But I haven't seen such refund policies on any game pages I saw. This is what confuses me
There is no drm on Itch. "Refunds" are a delicate topic therefore. Especially for works in progress. Even if your project does not run on the buyer's rig, it might run with the next version or the actual release version.
And if you do have a release version, you should know the specs pretty well.
I would upload a demo version to specifically give people an opportunity to test if they can run the game. And would consequently decline any refund claim for not being able to run the game. Should bugs be found, those can be fixed.