Firefox add-on doesn't work

[gbtami]

Ubuntu 18.04, Firefox 73.0 (64-bit)

[ExtremeWays2357]

Same in Windows 10. (FF 74.0, but has not been working for ages)

[rosstex]

Bump

[dmytrokyrychuk]

The add-on does not work both on Firefox and Chrome for me.

[Piturnah]

Still doesn't work

$ firefox -V
Mozilla Firefox 134.0.2

Using NixOS2 24.11