When you call this command from Menu Format, does it works? Try to delete KeyMap.ini (with not running PSPad) or from the menu format/ KeyMap press default button and restart PSPad.
You can also change shortcut in the proram settings / KeyMap -- <https://forum.pspad.com/read.php?6,78353,78407> PSPad freeware editor https://www.pspad.com
