No Audio on my Window/Display Captures

[NefariousStalfos]

I don't even know why it's happening. In yesterday's stream everything was going great, but in today's stream my game's audio was not being outputted to my stream.
In settings, I can't enable Desktop audio. Does anyone know what I could do or explain why this is happening?

I have a MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports) running macOS Catalina 10.15.5