heya! If you dont want to capture vtspog audio without fully capturing desktop audio you have in general two options.
The one we recommend is using this obs plugin here https://github.com/bozbez/win-capture-audio which lets you capture the audio of an specific program individually, once installed you need to capture the audio coming from vts-pog-helper.exe and you should be fine (this is the method I use myself)
The other method is by routing the audio through a virtual cable and then capturing that on obs and outputting that to your headphones/speakers, but its a a bit more complex and a bit unreliable, so I highly recommend that first method.
Hopefully it helps!