SUMMARY

X11 systemsettings/shortcuts/Custom Shortcuts empty, no way to add new custom shortcuts or command line options.

STEPS TO REPRODUCE
1. open systemsettings
2. select shortcuts
3. select custom shortcuts


OBSERVED RESULT
No entries, no way to add entries
EXPECTED RESULT
custom shortcut list and method for entering new ones with command lines.

SOFTWARE/OS VERSIONS

Linux/KDE Plasma:  
(available in About System)
KDE Plasma Version: 5.26.4 
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.7

ADDITIONAL INFORMATION
KDE is great because it's customizable. Custom shortcuts are powerful tools for users (me). Recent changes have made custom shortcuts difficult to implement and understand. Neither adding hot keys for scripts nor customizing inputs to applications are supported. The former shortcut exports, for example, included text descriptions of the shortcut key and associated commands, e.g.:
CommandURL=dolphin /home/mls/Dropbox/Papers\\ private/PDFs/  and 
Key=Ctrl+Alt+P

Now the custom shortcut list is in "custom shortcuts service",  added applications don't include scripts or command line options, exported shortcuts are incomprehensible KDE_NET_WM_ACTIVITIES strings  and  key chords, e.g.: 
{f5c8913d-7c80-4a3c-9a43-8f5536f2a479}=Ctrl+Alt+U

Please restore this functionality so users can easily create and modify keyboard shortcuts. The current implementation makes  KDE less useful.