Google has finally released the Android 11 Beta 3 update for the Pixel 4a. Google promised about the Beta update in their launch event of the device., and, they finally did it.
The Android 11 Beta 3 is quite stable for day to day live. But not stable as we see shipping in with smartphones or mainstream OTA updates. You can grab the update after you signup for the Beta program as of now. All you have to do is head here, to check your device eligibility and apply for the program.
Or, you can head to Android Developers page to download and sideload the OTA images directly.
Another way is to flash the OTA directly from Google website, Android Flash Tool. This is an official website by Google to flash Android Beta ROMs to your eligible smartphones.
Source: Android Central