My dually has 360 cameras and I just noticed on this video

that the trucks are having trailer guidance screen, that I would love to use for my camper, but my screen is not having the button. Look at 5:52 mark.
So for those who use their truck with the system. Do I need to have trailer connected to have the option, or I don't have it?
How the truck sense trailer connected? I am having the warning lights when I plug my camper, but that is too late to use the cameras.

 

You should be able to add a trailer to the system without the trailer connected, however the truck has to be stopped. I believe the trailer guidance view is to be used while the trailer is attached and is helpful to watch the sides as you back into spots your mirrors may not be able to see. The truck senses the voltage draw on the trailer wiring harnesses and know there is a trailer connected.

 

FOUND IT.
It will not show in main camera menu, but when in reverse, I can expand the menu and it works with no trailer plug.