How to enable/disable the API, if Unified Management is not being used.
Environment
App Control Server: 8.1.4+
Unified Management: Disabled
Resolution
Before Disabling: Verify with your infrastructure, that the API is not being used for reporting, unified management or any other uses. And that you are on server version 8.1.4 or higher.
Navigate in the console to Administration (Gear Icon) > System Configuration > Advanced Options