How to add and switch keyboard layout on Ubuntu 20.04 Desktop - LinuxConfig.org

In this guide, we're going to show you how to change your keyboard layout in Ubuntu 20.04 Focal Fossa. This will allow you to access the characters of another language and enable switching between multiple keyboards if you'd like.
This is a companion discussion topic for the original entry at https://linuxconfig.org/how-to-add-and-switch-keyboard-layout-on-ubuntu-20-04-desktop

How to fast switch without delay splash keyboard type screen ?