Revamping and mono DAW outs

Hello

I recently bought a UR824 and was wanting to send mono signals through the extra outputs… Anything above the main mix which uses outs 1&2.

I have been trying to send a dry signal out (what I assume) should be #3 DAW output… Which I have tried specifying in the vst connections area. I am attempting to send a dry guitar signal out to other hardware to be reamped.

For some reason I am currently not hearing anything out of that output. Is there something I am overlooking or something else such as the Ur control panel that also has to be configured to allow a track to send something there rather than the mains?