https://wccftech.com/android-p-developer-preview-4-now-available-for-the-pixel-and-pixel-2/

The fourth iteration of the Android P developer preview is finally here. We expected to see it a little earlier, but the timing is ok, considering Google rolled out the security patch for the month today. Like all previous releases, it is available only for the Pixel and Pixel 2. Other OEMs should follow suit shortly. Here is the list of known issues that the release has:

The factory images need to be sideloaded on to a device with an unlocked bootloader. You can find out more about how to go about it here. If you’re already a part of the beta program, you should receive an OTA that bumps the device up to the latest version. We wouldn’t recommend using it as a daily driver as the software is still in beta and several apps might not function as intended. It is called the developer preview for a reason, after all. The download links and additional information about the release can be found here.