Recording only game audio

Windows 10 21H1 and Later, Windows 11

1. Click the Settings button in the top right corner of the desktop client.
   
   
2. Click on the Recording tab on the left-hand side of the settings page.
   
3. Turn on Use Native Recording.
4. Turn on Use Per-Process Recording.
5. Under Processes to Record, you can turn on/off Record Game Audio if you wish to record the audio from your game. You can drag the slider beneath the checkbox to determine how loud you wish the game to be in your recordings.
   
   
6. If you wish to add other processes to record (e.g. Discord, Spotify, etc.), you can click the Add Process button () and select any currently running process.

Older Versions of Windows (NOT RECOMMENDED)

You will have to setup virtual audio cables. Check out this tutorial from Ludus Labs.