Hi. Sorry about that. We have uploaded keys to itch and other people have been able to claim them. The itch back end says "Keys will be distributed to a purchaser when they first click the request key button on their purchase page."
If you can't figure it out please email itch support as other people have got their keys that way. Failing that, please email us and we'll sort it out.
Thanks for your purchase, we hope you love the game!