No "Use all F1, F2, etc. keys as standard function keys" option in my keyboard preferences
I'm using a third party bluetooth keyboard and I have a usb windows keyboard. Does anybody know how to set up standard function keys (for either bluetooth or usb keyboard)? Is it exclusive to the official imac wireless keyboard? Holding my FN key doesn't change the function of my function keys, no matter the application they always adjust brightness and volume.
I have browsed the forums but the threads I read had more questions than answers.
What my system preferences looks like:
my system specs and version:
iMac 21.5", macOS 10.13