I am using Fedora distribution (Fedora 33)
Various untranslated string in my KDE desktop, while subversion has translation for those.

like apper:
rpm 'kde-l10n-pa' has no file for apper, while translated file is there since 2011.

https://websvn.kde.org/trunk/l10n-kf5/p ... ges/apper/

It is not just apper, but many other strings are untranslated in System Tray like (Keyboard Indicator), which is part of kdeplasma-addons/kdeplasma-addons._desktop_.po in SVN, but it is not in RPM

Already filed bug for Fedora, but looking for download link for all translated files.

This is indeed the kind of thing that needs to be reported to the distribution first, as we do not do the packaging of translations. Maybe a link to your bug report at Fedora here would be a good idea.