This game, as well as virtually every single NSFW game on itch.io and Steam, is now under censorship from payment processors. Just try to look for the "NSFW" tag, as time of writing literally only two games show up.
It's just infuriating how puritanism just keeps coming back. If you, like me, wanna do something about it, here's a petition: https://www.change.org/p/tell-mastercard-visa-activist-groups-stop-controlling-w...
The link is legit, I've checked it out recently. Hope if we can collect enough signatures, it's gonna be alright