Exhaust System Plastic Panel Replacement

Hello, everyone. There was a mishap with my prius that resulted in which the plastic panel beneath the exhaust system was torn off. I have a singular problem with getting this fixed, and that problem is that I simply do not know the name of the component/cannot find the name of it online. On the forums it is referenced in the same way I just did in this post. I need to know the name so that I can buy the replacement part online, as I would prefer to save money on this repair.
Any help would be appreciated. Thanks!