Also notifying @propter_hog@hexbear.net
You can cross-post by clicking this button of two squares, with one on top of the other.
This will lead you to a menu where you can change the content and title of the crosspost and select a community to crosspost to.
An alternative is to have both be the same and have one just be for people who want to contribute monetarily to your efforts or have the convenience of using their preferred store (if playstore is their preferred store). I think that’s sort of what Mindustry does (a foss game). It is available for 10€ on Steam, but also available for free on itch, with the steam version just having the benefit of being a steam game and having steam achievements. I guess ethically all is fine if you make clear that the game is also available for free from another place.
There’s also Forgêjo, which is a fork of Gitea.