If you want APM Server to connect to a cluster that has security features enabled, there are extra configuration steps:
You can use role-based access control to grant APM Server users access to secured resources.
You can use API keys to grant access to Elasticsearch more securely.
To interact with a secured cluster, APM Server must either provide basic authentication credentials or present a client certificate.
If encryption is enabled on the cluster, you need to enable HTTPS in the APM Server configuration.
For more information about security features, see Secure a cluster.