Unfortunately that a fake plastic OEM "Bull Bar" that very few 4TH Gens came with, it was an option and you will not find a replacement from Toyota because it's a discontinued part, if you're lucky you maybe able to find one at a savage yard, but I doubt it because of how few were sold as an option.
IMHO, if it were me I would just remove the bull bar and plug the holes in the "real" bumper.