Hey, thanks for your extension! It stopped working under current Firefox, until you use the "pin to toolbar" option as per .... support.mozilla.org/en-US/kb/extensions-button#w_manage-pinned-extensions

It used to work out of the box, but I still liked having the button added by "customize toolbar" but that option was completely replaced by this right-click option. Please check this, as I think you're not aware of it. BTW I use current ultramarine Linux with ff v133.0.3 .. I think without the icon, the extension can't notify and so decides not to block at all ... :(