How to assign keyboard shortcut for moving to next virtual desktop in kde plasma 5?
Kubuntu 18.04 and Kubuntu 19.04 use Ctrl+F1, Ctrl+F2, Ctrl+F3, and so on to change to the relevant desktop:
If you want to move to the desktop to the left or the right, assign appropriate shortcuts for those actions. If the keyboard shortcuts you input conflict with existing ones, the system will let you know.