After searching lots of screen recorders for Ubuntu, I found “Kazam” that works like a charm.

I like it because

1. Easy to install
2. Easy to use
3. Recording option with Speaker/Microphone
4. Recording Screen/Window options
5. Output videos size is optimum (approx 150 Mb for 60 min recording)
6. Easy Screenshot option

Install Kazam Screencaster on Debian /Ubuntu/Linux Mint

Kazam is available from Debian 11/Ubuntu 20.04/Linux Mint repository, just run the below command in the terminal.

sudo apt install kazam

Open Kazam from ‘Show Application’

• Sound from Speaker — when you want to record your host voice (and want to avoid your voice or your background noise, like fan sound).
  “Always use the inbuilt speaker or wired headset to record host voice for some Bluetooth headset it is not working”
• Sound from the microphone — When you want to record your voice too.

Go to File -> Preferences

Change Record with: Option to mp4, so that easily recorded video can be played with any popular media player like VLC.

Click on Capture to Start Recording

It will appear with a tiny icon on the system tray

By Clicking it you can Pause, Resume and Finish the recording

After finishing a pop up will appear to save the video

Press save for later and enter the desired location to save it and it's done, your screencast is ready.

You can do Screenshot as well

Please do a clap if it is really helpful to you.

P.S. — It’s my first article

Credit: https://www.linuxbabe.com/multimedia/install-kazam-screencaster