rear bumper "gap guard"

[ProStreet83C10]

hey guys, since putting my rear sport bumper on my truck ive noticed theres a pretty big gap between the bumper and the actual bed, showing a lot of the brackets and to me just creating a big "ugly space" The brackets have holes in the top side which look like they could be for some sort of a gap guard or gap filler, however, i dont know where to even begin looking for one at, if theres such a thing.

So, what im asking is IF there is such a piece to cover that area, what is it called and more importantly, where can i find one at to buy. I cant stand seeing right in between my bed and bumper and seeing those raw bumper brackets.