2011 Prius headlight fixture

I was changing the parking light bulbs on my daughter's Gen 3 Prius. On one side I noticed the high beam light was loose and a piece came off in my hand. It looks to part of the circular bracket the lamp mounts into. Looks like the bulb had come loose and actually melted the piece. Tried to upload a photo but the upload errors out.

My question is, does anyone know the name, or better yet, the part number of this piece? Other than the tight fit I don't think it should be a problem to replace it.

thanks in advance