The Apple A2566 charging case is specifically designed for and only compatible with the AirPods (3rd generation) .
It’s a 3rd Gen Case: Specifically, the A2566 is the MagSafe Charging Case version for the AirPods 3
Compatibility: It works exclusively with the A2564 (Left) and A2565 (Right) earbuds from the 3rd generation . It physically will not fit your A2031 (2nd Gen) or A1523 (1st Gen) earbuds.