Authentication and Authorization is provided by Adobe. There is a Turner "auth lib", a wrapper library around Adobe's AccessEnabler library, that handles Turner business logic.
See Auth Lib Docs for details on how to utilize the API.
See auth examples.
The Auth Lib observes the authLogLevel query param:
?authLogLevel=info
which sets the level of verbosity of console logging. The default setting is warn; setting to info will log calls to Adobe and callbacks called by Adobe.