I think the way itch does it, if you go to the purchase page and add the five additional dollars, it should give you access to the shining star download. Correct me if I’m wrong!
It'll make me purchase the game again, only this time I will have to pay an additional $30 instead of just the extra five, even though I already paid the full price. The last publisher sent me a link with the correct file and I simply paid $5 for their walkthrough guide. Here is a screenshot with what the purchase page says. I have also included my original purchase receipt.https://harlevin.itch.io/celestial-crowns/download/AwhJpn0ooYEFy13CbqNjvS8a1_4hN...