This loads an iframe from a website — (a remote web page running in the background)

And a popup: Shows a "Launch Tool" button that opens a bitly link that redirects to the same website

No ML model bundled. No local processing. No content scripts. It just points you to a website and runs it in a hidden iframe. The extension itself is essentially a bookmark with an icon.

This is not an extension for processing audio in Firefox in real time.
only jump to URL
https://vocalremover.org