Ussing existing commands in nativeui

Hello,
I want to create an menu via nativeui where you have the addonvehiclespawnmenu and the eup, and that those are in an submenu so it would say

NativeUI

Vehicle Spawner
EUP

But how can I use the command /eup in the submenu

In my opinion you can copy code from eup command and paste in function in NativeUI

That is not possible sometime