https://techcrunch.com/2020/02/19/google-launches-the-first-developer-preview-of-android-11/

With the days of desert-themed releases officially behind it, Google today announced the first developer preview of Android 11, which is now available as system images for Google’s own Pixel devices, starting with the Pixel 2.

As of now, there is no way to install the updates over the air. That’s usually something the company makes available at a later stage. These first releases aren’t meant for regular users anyway. Instead, they are a way for developers to test their applications and get a head start on making use of the latest features in the operating system.