Does anyone have an idea of how to upload a playable Javascript game on the browser no downloading files needed?

Been trying a lot of things: trying to put an emulator in the metadata (it would always say failed to configure emulator after pressing the button) and not putting one in at all (would say no preview available and required downloading files), entering a lot of different emulator names—I uploaded a zip with all the files needed, I've also tried contacting support two weeks ago but I have yet to receive a response, I'd appreciate the help