How to set up name for default template

[Adriann (Adrian)]

I have a configuration as shown below

#-------------------------- Elasticsearch output ------------------------------
output.elasticsearch:
  # Array of hosts to connect to.
  hosts: ["IP:9200"]
  username: "elastic"
  password: "elastic"
  # Protocol - either `http` (default) or `https`.
  protocol: "http"

  # Authentication credentials - either API key or username/password.
  #api_key: "id:api_key"
  indices:
    - index: "filebeat-netflow-%{+yyyy.MM.dd}"
      when.equals:
        event.module: "netflow"

    - index: "filebeat-cisco-%{+yyyy.MM.dd}"
      when.equals:
        event.module: "cisco"

I want to create rule for the default template.

I can read that there is a way to do that but I cannot find any use case example and all my tries fails. Can you show me the way?

Or is there a way to disable the default index that filebeat is creating event I don't want it?
It's empty and giving me error inside kibana dashboards that say one of my shards is not working properly.