hello v19 i have the same issus i paid the game here and the new version say i need a key.
There's a problem with how itch works.
If I change the game to paid, then people who bought the game can download their purchases, but then the game doesn't show up as having a free version anymore so I lose all traffic to the game.
I would assume itch won't help with this after they banned my payout possibility as it seems they really hate nsfw devs.
You should be able to download the game in your library now.