Hardtop power supply

[dickinsond]

I have a 2017

 

[amber.2]

What's the problem ?
If you don't explain we cant help ,

 

[dickinsond]

I have a 2017 pickup with a Burman hardtop. There is a multipin plug at the back left hand corner but it's not plugged into the vehicle and I cant find anywhere to plug it. I've had the rear light unit out but cant see anywhere obvious, can anyone help?