I was searchinf for information on how to setup a demo alongside of a purchasable game and I found this - https://itchio.tumblr.com/post/77827898339/offer-a-demo-alongside-your-purchasab...

But upon editing my game page I have no option to tick for demo.  Is this feature still available ?

Thanks.

It should be! Make sure you try with a paid game, not a free one.