You're looking to download Symantec Endpoint Protection Manager 14.3. Here are the steps and information you might find helpful:

The Symantec Endpoint Protection Manager is the management server component of the SEP suite. It communicates with the SEP client software installed on your endpoints (servers, desktops, laptops, and virtual machines). Key functions include:

Remember that SEPM is not a “set and forget” tool. Regularly review your dashboards, update your policies, and always keep a recent backup. With SEP 14.3, you leverage Symantec’s decades of threat intelligence in a stable, performant package.