dual display

I often play games with my friends on discord and we each are using Focusrite Scarlett Interfaces on Reaper to record mic audio alongside our video capture. However, we are unable to find a way to capture the audio of the monitor we are playing the game on but not the audio output from discord...

I have a Windows 10 1909 PC with the Laptop having a 1920x1080 and a second display of 1024x768. I am ONLY recording the 1920x1080 display and using the smaller display to hold the OBS studio main screen to control the display recording etc. The settings have been set as per the GPU issues noted...

on a dual monitor setup with my laptop but the thing can't recongnize the second display, however the obs does recognise the second monitor it is just not diplaying.