I bought it on Steam. Do I have to buy it again on itch.io to download it? Or is there a way to transfer?
Sorry, you do have to buy it again on itch.io to download it. I also bought it on steam and learned the hard way that you can't even install windows programs on mac, even if they let you buy it. On the bright side, its fairly easy to get a refund from steam, just fill out the refund form and tell them that the game doesn't work on your OS. I got the refund from steam within 3 days and used it to but Termina on here.