Glad to hear you’re enjoying the game!
Unfortunately, having payments enabled for an adult game - even just donations - on Itch means that the game gets hidden from search, tag browsing, etc. - basically only making it possible to find through collections, user pages, or links from outside Itch. This isn’t a game I’m really trying to make money off of so it just seems easier to leave payments disabled altogether.
If you’re really interested in donating I do have a Patreon page (OpenFlyGames), although I’m running a bit behind on actually running new posts at the moment.