right/left amiga keys to right/left cmd on Apple keyboard
 

I'm trying to map the right and left cmd-keys on an mac keyboard to left and right amiga keys.
I tried
keyboard_key_kpmenu = action_key_amiga_right
keyboard_key_kplalt = action_key_amiga_left
and some other variations taken from here https://fs-uae.net/docs/keyboard
but cant get it to work.

OS is Ubuntu 17.10, FS-UAE is latest stable, 2.8.3

What am I doing wrong?

Not sure about the Mac keys as I use a Win laptop.
I have mapped the right & left Amiga key to the "Windows" (left) & "Menu" (right) key on the keyboard with the following :
Here you can check the config I use containing the other mapped keys as well. Hope it may be of any help.