Despite claiming to be configurable on a per-site basis, I was unable to determine how to do this (extensive searching). And, if the extension's icon is supposed to be visible, it is not on my system (FF 121.0), and while I can find it in the overflow "Extensions" button on the toolbar, it is greyed-out and unresponsive. I uninstalled it after an hour, as I need its capabilities for ONE site, not all sites, and it does not appear to have this capability.