I currently have a Let's Play Channel on Youtube, so, I need to record gameplay footage (video and audio) along with microphone audio (in a separate file, with audacity).

I found a software called Simple Screen Recorder (SSR) to record gameplay video and audio footage, I have checked the website for instructions on how to adjust the things and the problems began.

First, the video is recorded just fine, it's the simplest software I could find to set up the configurations and get it up and running. Problem is, no gameplay audio, no system audio. Audacity records the microphone just well, so I started to take a look on the configurations on PulseAudio Volume Control while recording something with SSR. Many tutorials tell to change the audio imput to Monitor of Built-in Analog Audio in order to record the gameplay audio, but this did not work to me here.

I suspect that this Monitor of Built-in Analog Audio is not configured or that it does not have audio to be recorded at all, how can I fix this?