The console needs to be served, not opened directly

You are seeing this because the page was opened straight from disk (a file:// address). Browsers refuse to load JavaScript modules that way, so nothing could start. This is a browser security rule, not a fault in the tool, and it is why you got a page instead of a console.

Serve the folder over HTTP and it will work. From this directory:

python -m http.server 8123

Then open http://localhost:8123, and stop the server with Ctrl+C when you are done.

Hosted copies are unaffected: on a normal web address everything below loads by itself. If you are seeing this on a hosted copy, then a script genuinely failed. Open the browser console for the error.