Install kdesignerplugin-data by entering the following commands in the terminal:
sudo apt update sudo apt install kdesignerplugin-data
Description:
Integration of KF5 widgets in Qt Designer/Creator
This framework provides plugins for Qt Designer that allow it to display the widgets provided by various KDE Frameworks, as well as a utility kgendesignerplugin which can be used to generate other such plugins from ini-style description files. . Part of KDE Frameworks. . This package contains images and translations.
Homepage: https://projects.kde.org/projects/frameworks/kdesignerplugin
Version: 5.44.0-0ubuntu1
Section: universe/libs