Integrations
Calling Alodai from your own code, and pointing your own domain at a platform.
Two services accept an organization API key and can therefore be called from your own code: core and sites. Every other publicly-routed service refuses one.
That is not a recommendation, it is the shape of the system: the list is derived by scanning the services for the code that installs a key validator, and a check fails if the list and the code disagree in either direction.