How to increase the archive of .monitoring-es-6 indices?

Elastic Stack Kibana
1

We are currently using versions 6.5 of elasticsearch and kibana.

Since I need to monitor the server, I want to set the storage period of monitoring indices to 30 days.

[ kibana dev-tools]
PUT _cluster/settings
{
  "persistent": {
    "xpack.monitoring.history.duration": "30d"
  }
}

 [ elasticsearch.yml ] 
xpack.monitoring.history.duration: "30d"

Even though I used the command and elasticsearch.yml options listed below, it seems that data is only kept for up to 7 days.

Can’t users using the free version keep data for more than 7 days?