Steam and Itch are competitors and Steam doesn't want key trading like that to happen. And they also don't deal in Android builds. Because of that we can't have a way to make a Steam purchase give Android content. Unfortunately, you would have to try to get a refund on Steam and buy them here or not be able to use the Android version. I'm sorry. But there are pros to Steam that Itch doesn't have, so it's not a total loss to get it there.