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