This site is monetizing my game without permission. What do i do?

It's open source (gpl 3) so I'm pretty sure this is illegal, has this happened to anyone else?

github: https://github.com/Jimm144/pixel-run (pls star)

game: https://pixelrun.localplayer.dev/

here's description: Endless runner that plays in the browser. Jump, double-jump and dive through four biomes, stomp enemies, collect coins and beat your best score.

I don't make money off the game but I'd rather them not do this