Configure a "widows" key on a 120-key keyboard

[Van Snyder]

I use an IBM PS-2 keyboard, the kind with 102 keys, and therefore no
"Windows" key.

How do I set up a windows key, for example "Pause" or "Ctrl-Pause"?

I tried

XKBOPTIONS=Pause:Menu

and

XKBOPTIONS=pause:menu

in /etc/default/keyboard but those didn't work.