In this final installment of a series on monitoring system metrics with the Elastic Stack, the focus is on ingesting metrics securely using role-based access control (RBAC). The process involves setting up specific roles and users with minimum necessary permissions, rather than using a superuser, to enhance security. Two roles, metricbeat_setup and metricbeat_writer, are created, each with different permissions for setup and data writing tasks. Corresponding users are assigned these roles, ensuring they only have access to the permissions required for their tasks. The use of a keystore is recommended for securely storing credentials, avoiding plain text exposure, and allowing for flexible deployment configurations. The article encourages users to get started by signing up for a free trial of Elasticsearch Service or downloading the Elastic Stack for self-hosting, offering further support through forums for any queries or challenges.