You are prompted during the client installation to do it if needed. As of macOS 10.13, you must authorize the Symantec Endpoint Protection kernel extension after installation for Symantec Endpoint Protection to fully function.Mac clients for Symantec Endpoint Protection Cloud do not support Mac OS X 10.11 (El Capitan).See Remove Symantec software for Mac using RemoveSymantecMacFiles.
Note: Different product versions have specific system requirements. SEP 14.x Client for macOS/OS X Compatibility Chart