OUTPUTS 3-4 NOT SHOWING

Hi ,

Wish somebody can help me. I cannot see an option to set my output for 3-4 in my DAW. I can only set my outs to stereo out 1-2 with my UR22.
Any other solution to routing an instrument without entering my main stereo out, will be very appreciated.

I want to hear my metronome clicking but I do not want it to enter into my main stereo out the channel in my DAW, to leave my main stereo out for monitoring the headroom of all my other instruments, without the continuous feed from my metronome.

BEST
Brian