Use this call to obtain consent to invoke the API on behalf of the user. It will require you to authenticate as a CMS user and obtain consent, unless consent has been previously stored and still exist in the project.
To make an Access API call from the external projects such as custom web or mobile applications, you must supply an API key as well as the instance name and credentials on the authentication call.
Specify one or more of the following HTTP headers in the API calls:
Required. Specifies the authentication API Key that proves you have access to the CMS instance. You specify the API Key in the Authorization request header.