How to upgrade the firmware version
How to upgrade firmware of AirPods Pro ver2 using iPhone
Question marked as
I don't think there is any manual process for this.
Firmware updates are delivered automatically while your AirPods are charging and in Bluetooth range of your iPhone, iPad, or Mac that's connected to Wi-Fi. You can also use your iPhone, iPad, or Mac to check that your AirPods have the latest version.
About firmware updates for AirPods - Apple Support (IN)