Wireless keyboard not connecting to iMac
Wireless keyboard not connecting to iMac
Question marked as
To fix a wireless keyboard that will not connect to your iMac, plug it in with a Lightning or USB-C cable (if it is a Magic Keyboard), check the power switch or batteries, turn Bluetooth off and back on, and re-pair the device
See this for further reference
If you can't connect your Magic Keyboard, Magic Mouse, or Magic Trackpad to your Mac - Apple Support