: Your GLPI server must have outbound internet access to contact services.glpi-network.com to validate the key and download plugin lists. Registration key marketplace | Tutorials | Help Center GLPI
You will not be able to recover it easily through the portal; you would need to re-register. glpi registration key
Think of it like the update keys used in Linux package managers (e.g., apt-key ). The key does not "activate" your software; it simply tells GLPI, "It is safe to check for updates from the official repository." : Your GLPI server must have outbound internet