Android 12L rolling out to Google Pixel phones

Android 12L is a special drop that makes Android 12 even better on tablets and foldable devices and it is now available on Pixels phones

Google has confirmed that the March update of smartphones from the Pixel line is based on the Android 12L code. The problem, however, is that these devices are neither foldable nor tablets, so main features are not available on them.

more:
https://developer.android.com/about/versions/12/12L

Android 12L Beta 1 goes live for Google Pixel phones

Android 12 arrived in October and was shortly followed by an Android 12L developer preview. Android 12L is a feature-drop update specifically designed to bring several optimizations and improvements for foldable and large screen devices. The Beta 1 is available for all Pixel devices starting from Pixel 3 up to Pixel 5a. We need to wait for Android 12L Beta dedicated for Pixel 6(Pro).