I can not go into full screen mode in level editor

Hello. I am on a MAC laptop. I can’t seem to go into full screen mode in level editor. it is supposed to be with F11 but when I click F11 or shift F11 all it does is turn the volume down on the computer. thats the computer shortcut but i can’t get it to work for UE4. I don’t know what version I have, other than that I just downloaded it last week so I’m assuming it should be up to date.

Is there a function key on your keyboard if so try using that?

Otherwise this is a possible solution: