Bug 438088

Apper currently does not show the Translators tab in its About dialogue.

1) Tested with Apper 1.0.0 (KF 5.82.0, Qt 5.15.2, Archlinux build)

2) We have already 100% translated Apper to Simplified Chinese (zh_CN) a few months ago. "Your names" and "Your emails" have been filled. 

3) The app displays our translation properly, just without the Translators tab in its About dialogue.

There is a related bug report which discussed a similar issue in Elisa and digiKam as well:
https://bugs.kde.org/show_bug.cgi?id=437738#c15

Albert Astals Cid said:

(For Elisa) That's an elisa bug, open a bug for them, they either need to use KMainWindow (or some class that inherits from it) or call
      setTranslator(i18nc("NAME OF TRANSLATORS", "Your names"),
                    i18nc("EMAIL OF TRANSLATORS", "Your emails"));
manually on their KAboutData as stated in the KAboutData documentation

(For digiKam) it works on the last official release both using appimage and not using appimage, if it doesn't work on the nightly, i'd say that is their bug and not a kxmlgui bug either.

(For Apper) I'd say it's the same problem of not using KMainWindow or similar (at least i can't find one)