@BTRADIOADDRESS is a TCC function that returns the address of the Bluetooth radio whose index is n is discoverable.
@BTRADIOADDRESS[n] : Returns the address of the Bluetooth radio whose index is n is discoverable. (Indexes range from 0 to _btdevicecount.)
Example:
echo %@btradioaddress[0]
00:E0:4C:70:3A:03