The AirPods generation are wireless headphones, and their charging cases usually use the standard Lightning charging port instead of USB-C, so PD (Power Delivery) fast charging is not possible. PD Fast Charge is a fast charging technology based on the USB-C standard that requires compatible devices and charging cables. If your AirPods generation charging case has a Lightning port on it, you'll need to use the standard Lightning cable to charge it, not the PD fast charge. If you use a mismatched charger or cable, it may cause poor charging or damage the device.
It works except it's a normal charging speed