Apple had updated the firmware for its AirPods, AirPods Pro, AirPods Max, and MagSafe Charger devices. The tech giant doesn’t provide release notes for its firmware, so it’s assumed they provide bug fixes and performance tweaks.
Regarding the audio devices, installation is automatic when the AirPods are in their charging case, the case is plugged into a charger, and the linked iPhone is in close proximity and connected to Wi-Fi. You can check the installed firmware revision in the “General” settings menu, by selecting “About,” then “AirPods.” AppleInsider says the update contains “miscellaneous minor bug fixes.”
Regarding the MagSafe Charger, as best I can tell to make sure the firmware upgrades, it needs to be plugged in and connected to an Apple device.