Havent hooked to a gooseneck yet as I only had the truck a month. But I’m going to be super careful backing up to one.

It looked like that was what happened.

 

I work in the collision repair industry and with a crack like that on an aluminum panel, good luck finding a shop that is willing to weld it up. You will probably have to go to a hack shop and most of those don't have the equipment for aluminum anyway. I looked at the picture real quick but it looked like the floor of the bed so they will most likely replace that, especially with those body lines that the crack is going over. If it was on a flat piece of aluminum you might have better luck repairing it.