I see! That's odd. Is the page recognising the bought the game and offering the option to download the main game, but it just isn't downloading? Or is the option not there at all?
Did you buy with the account you're posting with and get an email confirming the purchase went through? As I do a search on my records for your username and can't see anyone recently. So it's possible it may be an issue on itch.io's side than mine.