fn key is greyed out on Ventura 13.1

How to enable fn key in the modifier keys list - it is greyed out?

This should still be the case for Ventura. ( System Settings => Keyboard => Press FN Key to Expand Control Strip)

This allows for the fn check box option to become accessible, but does not work when I try to create macros of function keys from F1 to F20 on Touch Bar when pressing fn key. Nothing shows up on the touch bar when I press the fn key.