Today, Apple has updated the firmware version of the AirPods.Official List
To update the firmware, just putAirPods headphones into the battery case and close the cover, then connect the case to the charger or USB port of the computer and wait for a few minutes. Your iPhone must be paired with AirPods and connected to a Wi-Fi network in order for the updated firmware to download and install.
To see the current headphone firmware versionAirPods, open the headphone cover and when the connection picture appears on your iPhone, tap “Settings” → “General” → “About this device” → “AirPods”.
More information on the AirPods headphone firmware version can be found in the manual.