If you’re looking for a screen recording app for the Raspberry Pi, Kazam seems to be the best (only?) one available.
To install, open a terminal and type: sudo apt install kazam
After this this is finished, typing kazam into the terminal will probably fail with a series of errors relating to Gtk 3.0 and pulseaudio.
Whilst pulseaudio isn’t required to record the screen, it is required to record and playback audio. To fix this, type sudo apt install pulseaudio to install it. The next step may or may not be required but I found it useful anyway – type sudo apt install python3-xlib to install the xlib python 3 library.
You’ll then need to start pulseaudio as a system service and start the daemon on boot. To do this, type sudo pulseaudio –system -D, then type sudo reboot now.
If all goes well, after your Pi restarts, next time you try and launch Kazam from the Applications Menu, it should show the window.
For video recording, I’ve found the HUFFYUV (AVI) codec at 15fps works ok.
All of the above was done on a Raspberry Pi 4 Model B 4GB with a 16GB SanDisk micro-SD card running Raspberry Pi OS 32-bit version May 2020.