I've heard a few people who are in the official Discord mention that the devs said there (and as far as I can tell, only there) that they're no longer supporting the itch.io version of the game.
If you bought on here, and if you can use Steam, the "download" button at the top of the page takes you to a page with a Steam key. Not everyone can use Steam (in my case it's been a known health hazard for 18 months and Valve still refuses to do anything except block users from having any safe workarounds we can use), but if you can, it's an option.