Install gxkb by entering the following commands in the terminal:
sudo apt update sudo apt install gxkb
Description:
X11 keyboard indicator and switcher
gxkb is a little indicator applet which allows one to quickly switch between different keyboard layouts in X. A flag corresponding to the country of the active layout is shown in the indicator area. . The applet is written in C and uses the GTK+ library and therefore does not depend on any GNOME components.
Homepage: https://zen-tools.github.io/gxkb
Version: 0.8.0-1
Section: universe/x11