Power ring siren

I have bought the plug in power supply second generation to power my outdoor ring siren, now I know now i still need the d cell batteries installed. But i was under the impression that I did not need the quick release battery installed, as i was wiring it with the power supply after talking with ring customer support over the phone.
I just double checked with the ring chat application, and Mohamed informed me i need to install the quick release battery as well as the second generation power supply.
Could anybody advise me as I’m getting conflicting advise from ring.
Regards rob

The battery is completely optional when you hardwire - it can act as a backup for dusk to dawn if the power goes out - the d cells act as a backup for the actual siren regardless. The battery is only required with the solar panel.