Install breeze-icon-theme by entering the following commands in the terminal:
sudo apt update sudo apt install breeze-icon-theme
Description:
Default Plasma icon theme.
This is the default icon theme for the KDE Plasma 5 desktop. . This package is part of the Breeze theme module.
Homepage: https://projects.kde.org/projects/kde/frameworks/breeze-icons
Version: 4:5.44.0-0ubuntu1
Section: universe/kde