Hmmm ok. I think there would be some sort of integration with an api, but that doesn't seem to be the case. Thanks for the reply!
Viewing post in IAP in itchio
Haha funny you mention it, I actually have a thread suggesting they update the Reward system into the API so it can be used for in-game content XD
https://itch.io/t/75228/suggestion-rewards-api
If you agree it'd be a cool system I'm sure them seeing some comments in the thread would make it more known to Amos and Leafo ^_^