I have square Hole in my old tub, Looks like some kind of plate or cover is missing. What is it called.?

Question

The Hole is above the drain. Below the faucet. It's squre about, 4 inches Square. Looks like there was a square plate or some kind a cover over it at one time. Trying to find the correct name of the part or how to fix it.

Answer 1

This would be the overflow. This should have pipe behind the tub connecting the overflow to the drain pipe.