Just a reminder, that the handbook linked in Help / Kleopatra Handbook is very old: Revision 2.1.1 (KDE 4.11) (2013-07-04):
https://docs.kde.org/stable5/en/kleopatra/kleopatra/index.html

Now with KDE 6 and many changes to the menu structure and user interfaces, it might do more harm than be useful.