How to connect keyboard to Mac mini

The Logitech K850 keyboard offers dual radio frequency connections via its non-Bluetooth dongle, and by Bluetooth (typically to tablets). Whether the Bluetooth radio is compatible with your Mac mini (or any Mac), is an oustanding question as I do not have the K850 keyboard here.

I have had Logitech mice in the past that were entirely dependent on the radio connection to the USB port dongle, and fresh batteries.

I have an old wired usb keyboard for when I get into such issues, it's just an old windows layout usb keyboard I only use for this purpose