Where do CN-Series devices obtain a VM-Series authorization key?

CN-Series devices obtain a VM-Series authorization key from Panorama. Panorama is the centralized management platform for Palo Alto Networks firewalls, including CN-Series and VM-Series. It provides the necessary authorization keys and other configurations to ensure proper deployment and operation of the firewalls.

References:

Palo Alto Networks Panorama Documentation: Panorama Overview

Palo Alto Networks CN-Series Setup Guide: CN-Series Setup