itch.io

got it! Thanks for clarifying 

Foundry is a virtual tabletop software that allows people to play tabletop roleplaying games online. A  module is a modification to that software that changes some core functionality; in my case a free module that randomly generates items like weapons, armor in the players' game. Because the module is public, it would give anyone who uses it in their game unpaid access to your art assets.

I would place attribution credit and a link to your itch.io, both in the module and on Github repo which hosts it. Given this clarification however, I more than understand if you change your answer. Thanks for the speedy response, and please let me know either way.

Hello! Could you clarify what constitutes commercial use? Could they be used in a game or as part of a foundry vtt module with attribution?