Apple released new support documentin which she talked regarding changes in firmware 2.0.34 and 2.0.36 for AirTag.
In 2.0.34, the company finally added the Precision Finding feature announced at the beginning of last year. When the iPhone detects an unknown AirTag moving with the user, the person can use the new option in combination with an audible alert to quickly find and disable that AirTag.
The function allows you to determine the exact distance and direction to the mark. You need an iPhone 11 or higher to access it.
Concerning updates 2.0.36released on December 13th, it fixes an issue where the accelerometer built into AirTag would not activate in certain scenarios. It is probably used to determine the movement of the AirTag. [9to5]