Not sure why, but I've updated things my end, just in case. Give it a try!
Recent community posts
Information online seems to vary. Itch.io should show a 'request key' button either on the main AWCA page, the Download page or on your purchases page.
If it still does not appear, please email me from your paypal email address at email@example.com and I'll send a code.
EDIT - I'm showing some redeemed keys, so it must be possible!