Here is an extremely well documented guide on installing OBS Studio on your Raspberry Pi 4. I tried it and was successful in stalling. I even had the video driver error and was able to overcome it with “MESA_GL_VERSION_OVERRIDE=3.3 obs” as the guide suggested.
The only issue I found was that the icon under “Sound & Video” does not work. You have to type “MESA_GL_VERSION_OVERRIDE=3.3 obs” in a terminal for OBS Studio to work.
Alternately…you can install piKiss, which has an easy way to install OBS Studio. There’s a guide here. Once installed, navigate to “Multimedia”, and then “OBS”. With piKiss, you can also install many games, emulators, tweaks, multimedia programs and more. Very interesting program!