Install kde-l10n-km by entering the following commands in the terminal:
sudo apt update sudo apt install kde-l10n-km
Description:
km (km) localization for KDE
This package contains the translation files for all KDE core applications for the language "km".
Homepage: http://l10n.kde.org/team-infos.php?teamcode=km
Version: 4:17.08.3-0ubuntu4
Section: universe/kde