What's this plug hole behind the refrigerator for?

The power socket shown in the figure is used for the power socket inserted into the power supply line of the refrigerator when the products of the refrigerator manufacturer leave the factory, which plays a protective and fixing role; It is disposable, and this socket is useless during the use of the refrigerator.

Some refrigerator manufacturers also put transparent plastic sleeves on the three pins of the power plug of the refrigerator power cord to protect it.