Just bought and need help figuring out ehat part is missing from circled blue area their is nothing covering what I believe is the ac confessor. I ordered a screen for the top grille but not sure what to order for the bottom thing

 

There is nothing missing. That's the way they are built. Why do you think you need something there?

 

Okay thought it was since it seems like it should to avoid flies getting caught in it , thank you