How to control volume on Philips monitor So I just installed a 48" monitor with extended display in my home office, however, I can no longer use the f10 - f12 keys to control the volume.

I a colleague provided this guide:
https://www.lifewire.com/select-audio-in-and-out-from-mac-menu-bar-2260855

This did place the volume icon in the menu bar, but its greyed out. I still cannot change the volume.

Any suggestions?
The volume for most displays can only be controlled externally (i.e., from the monitor itself).

However, there is a workaround that is documented at Lifehacker.