recordbox on PC want tohear via stereo device

Hi

i have a pioneer networkplayer connected to my PC.

I can hear music on my stereo in my room this way.

My problem I could not figure out, how I can hear recordbox (just the programm, without a DJ controller) on this. When I have my networkplayer on music server, I find no option to it in the recordbox-settings.

Can someone help me?