Google’s latest Android 16 Developer Preview 2 brings a convenient feature that allows users to unlock their Pixel 9 smartphones without turning on the screen. This new feature, found in Settings > Security & privacy > Device unlock > Face & Fingerprint Unlock > Fingerprint Unlock, takes advantage of the ultrasonic fingerprint scanner in the Pixel 9 series, eliminating the need for light.
This feature is exclusive to the Pixel 9 and doesn’t appear in older devices like the Pixel 8 Pro. Users can still enable the “always-on display” setting on their older Pixel devices to achieve a similar effect, which keeps optical sensors active even when only displaying time. This new feature is a significant win for convenience, allowing users to quickly access their fingerprint sensor without waking up their screen.
Source: https://www.digitaltrends.com/mobile/android-16-adds-new-way-to-use-google-pixel-9-fingerprint-sensor