Just a heads-up: When I try to access the game's page on the Itch app at the moment, I get a blank screen with no purchase option. All I can do is install the demo, though the page loads normally in Chrome (and the purchase option is there).
Maybe this only affects me for some reason, but I thought I should mention it in case this may prevent other Itch app users from purchasing the game. Maybe ask some Itch app users on you Discord to test if this affects everyone using the app?