How does it do that? Does it send an alert to your phone too?
Unknown Tracker Alerts
This feature is available on Android phones running Android 6.0 or later. To use it, you can:
Go to Settings
Tap Safety & Emergency
Tap Unknown tracker alerts
Tap Scan now
Turn on “allow alerts” to receive automatic notifications
When an AirTag is detected, you can:
Open the map to see the location of the AirTag
Tap Play sound to make the AirTag play a sound to help you locate it
Tap Next steps and follow the onscreen instructions
https://www.pcmag.com/news/iphones-android-phones-can-now-detect-more-rogue-bluetooth-trackers