The zip file you provided must have a file within it called index.html that is your game’s entry point. You must make sure that you’ve exported your game to the HTML target in order for Godot to generate that file.
I just checked the zip file you have uploaded on your account and I see a file named index.html.html. It looks like you renamed the file in a way that gave it two extensions. If you ensure it’s called index.html your game should be loadable.
Hope that helps