Wall adhesive failed

Hello, I don’t know what this part is called but it’s the support for the side wall of the van. It has come unstuck which I think has been caused by a dent in the side. Could anyone recommend what I stick this back on with please? I have tiger seal adhesive and sticks like sh*t, but wanted to see if you would recommend something else?

Thank you

Sikaflex 252. Comes in black or white and is used in the automotive industry to bond metals,etc. Flexible but strong. Fiamma recommends it in attaching their awnings. A little expensive but you’ll only have to do it once.

Brilliant, thanks very much!