If you use Safari on desktop, you can enable WebGL 2.0 if you turn on the Develop menu in settings, then enable it in the experimental features Develop menu.
I can't get the server to connect when attempting to try, but the demo youtube is extremely cool.
Are you on Linux ? There is a known issue on Linux with the server running in background when you launch the AppImage directly (by clicking on it) so it is actually launched but you can't see it and if you launch it a second time it will fail to listen because the port is already busy with the first one, the AppImage must be launched in a terminal.