If you are using Onyx+ you will need to connect through Buttplug initface - via the steps here →
" OPTION 3 -
HOW TO CONNECT WITH YOUR KIIROO KEON (Launch or 147 other toys) AND VR (WIRED OR MOBILE!) HEADSET USING PC BLUETOOTH WITHOUT ANDROID DEVICE to DEOVR/SLR APP"
Once you get to this step:
“Click the ‘Devices’ tab → then click 'Buttplug / Initface” → then click “Scan For Devices” "
Just sometimes takes a clicks to retry Scaning for devices if it doesnt pick it up at first, or reclose everything, and just retry again