Volume control by Mac's keyboard?

I control Roon (1.3/276) primarily through my iPad, no problem with that. Sometimes I listen to music sitting in front of my iMac and wish to control the volume from the keyboard, but I can’t find a Roon setting that would allow this. Besides the “fixed” setting all others only make volume controllable from Roon remote (iPad).

Roon > Dirac Audio Processor stereo > Built in output

OS 10.13.2

My keyboard and mouse are connected by Bluetooth.

What do I miss?

In Roon on your iMac …

Settings > Keyboard Shortcuts

Thanks. But this only works if Roon control on my Mac is open.

Why wouldn’t the keyboard volume control work actually?

I’m not 100% sure why the keyboard volume keys don’t work in in Roon, but I suspect it has something to do with all the different possibilities for volume control that are inherent in any Roon-centric system.