The jam time expires in 40 minutes, so you should have time to edit the game and try it out.
If you used Unity to make your game you can build the game as Web GL, select all of the build files in the build directory, right-click "Send to zip", and upload the zip file.
I don't know how other engines work when trying to submit the game.
Make sure to check the "This files plays in the browser" checkbox below the uploaded file.