I'm trying to map the special 'FN' key on a Logitech K360 keyboard to 'Mod3' in the i3wm window manager on Debian. However, I can't find the keycode for the 'FN' key. Showkey and xev don't return any value when 'FN' is pressed. However, the FN key does work and returns different single values in line with the FN default settings. For example, xev and showkey shows 'End' when I press the End key, but returns 'Pause' when I press FN+End.
Solaar doesn't seem to have any settings that help with this.
How do I get the keybind for 'FN'? Thanks.