How I can assign shortcut to some Editing actiing

Hi all,

Some editing actions (Tools → Scripts → Editing or Right Click → Editing) has shortcut - for example Move Lines Down → Ctrl + Shift + Down
But many of them don’t - for instance Duplicate Selected Lines Down

In this case I want to assign shortcut to Duplicate Selected Lines
How I can do this ?
I don’t find this action in Keyboard shortcuts .