I am new to game jams and I don't really use unity of play canvas or anything like that. I am only able to make something for this on scratch and I am looking for a team!
It says Windows WebGL. There is a tool that let's you convert your scratch game to HTML, meaning you can probably use that to build a package and post it there. As long as it's compatible with browser I think they will count it: https://sheeptester.github.io/htmlifier/