By the client do you mean the app? Do you know if you're trying to download it directly from the Fortune-499 page or from the bundle page? I know that itch doesn't actually add the games from the bundle to your library until you tell it to (to avoid flooding your library with stuff), so it won't give you a download link on the game's page and you need to find the game in a separate bundle page to get the download link (it seems to work this way both on the itch site and on the app, from what I can tell).