I'm currently installing it via OTA.
Official announcement: https://support.google.com/pixelphone/thread/175255708/google-pixel-update-android-13?hl=en
ROM builds: https://developers.google.com/android/ota
Official announcement: https://support.google.com/pixelphone/thread/175255708/google-pixel-update-android-13?hl=en
ROM builds: https://developers.google.com/android/ota