Packetbeat - Cannot add kubernetes metadata

Hi.
I am trying to configure packetbeat 1.10.1 in order to get kubernetes metadata in a kubernetes cluster v. 1.18.3 but I am not able to get it.

This is the configuration that I have applied:

       - add_cloud_metadata:
       - add_kubernetes_metadata:
           host: ${HOSTNAME}
           default_indexers.enabled: false
           default_matchers.enabled: false
           indexers:
             - ip_port:
           matchers:
           - field_format:
               format: '%{[ip]}:%{[port]}'

I also tried with the default indexers and matchers without any success.

The logs show the following information without any error:

  INFO    [kubernetes]    kubernetes/util.go:99   kubernetes: Using node ip-xx-xx-xx-xxx provided in the config   {"libbeat.processor": "add_kubernetes_metadata"}.

Is there anything that I am missing in the setup, or any other consideration to take care of?