After finishing the recording desktop with OBS, you can find recorded videos and edit the OBS recording in whatever way you like. By default, screen recordings are stored in the location where OBS is installed. If you do not know where the installation path is, you can clickFileon the top...
Just for the record, I used REAPER and a huge pack of audio loops I got in a Humble Bundle a few months back to make all of these. I used a visualization tool called projectM and OBS to make the videos. References: Detroit Become Human demo, Out of Place demo, and Into The Breach...
Commenting here as I've the same problem. I think it does only show that one file (no separate .wav file) but when you drag it to your video editing program, it will automatically split into three tracks: Video, System Audio, and Mic Audio. It's shown here: (DISCLAIMER...