I use this great add-on very often. But it looks as if it is not working any more with ff 136 and above?

Great extension! I have it putted on my third-party status bar and it reminds me how Mosaic, Internet Explorer, Netscape or some other browsers in '90s handled the Page Source, through button on very left of the status bar.

Handy easy way to view.Good job,thanks.
(btw:it's perfectly working from Context Menu in mobile)