MetricBeat could not connect to a comptaible version of Elastisearch

I'm trying to install OpenSearch stack to ship data and visualize then on their Dashboard. Everything is locally for now.

I have installed Core, Dashboard and the service run.

Next I want to send metrics to follow CPU, RAM, Disk, Network... with MetricBeat OSS. I have setup Core to mimic Elasticsearch7 beacause it's seems to not reconize OpenSearch as it is.

curl -X GET "http://localhost:9200"
{
  "name" : "node-1",
  "cluster_name" : "opensearch-demo",
  "cluster_uuid" : "MdYUP-7gTrqKf58qW8XY7g",
  "version" : {
    "number" : "7.10.2",
    "build_type" : "rpm",
    "build_hash" : "2e4741fb45d1b150aaeeadf66d41445b23ff5982",
    "build_date" : "2025-02-27T01:16:53.890803852Z",
    "build_snapshot" : false,
    "lucene_version" : "9.12.1",
    "minimum_wire_compatibility_version" : "7.10.0",
    "minimum_index_compatibility_version" : "7.0.0"
  },
  "tagline" : "The OpenSearch Project: https://opensearch.org/"
}

When I run metricbeat I keep havig this error :

{
   "log.level":"error",
   "@timestamp":"2025-03-14T14:26:42.758+0100",
   "log.logger":"publisher_pipeline_output",
   "log.origin":{
      "function":"github.com/elastic/beats/v7/libbeat/publisher/pipeline.(*netClientWorker).run",
      "file.name":"pipeline/client_worker.go",
      "file.line":149
   },
   "message":"Failed to connect to backoff(elasticsearch(http://10.29.165.222:9200)): Connection marked as failed because the onConnect callback failed: could not connect to a compatible version of Elasticsearch: 400 Bad Request: {\"error\":{\"root_cause\":[{\"type\":\"invalid_index_name_exception\",\"reason\":\"Invalid index name [_license], must not start with '_'.\",\"index\":\"_license\",\"index_uuid\":\"_na_\"}],\"type\":\"invalid_index_name_exception\",\"reason\":\"Invalid index name [_license], must not start with '_'.\",\"index\":\"_license\",\"index_uuid\":\"_na_\"},\"status\":400}",
   "service.name":"metricbeat",
   "ecs.version":"1.6.0"
}

Here my metricBeat conf :

sudo nano /etc/metricbeat/metricbeat.yml

metricbeat.config.modules:
  # Glob pattern for configuration loading
  path: ${path.config}/modules.d/*.yml
  reload.enabled: false
  module: system
  period: 10s
  metricsets:
    - cpu
    - memory
    - process
    - filesystem
    - network
  enabled: true
  xpack.enabled: false

setup.dashboards.enabled: false
setup.ilm.enabled: false
setup.template.enabled: false
setup.template.settings:
  index.number_of_shards: 1

output.elasticsearch:
  # Array of hosts to connect to.
  hosts: ["10.29.165.222:9200"]
  protocol: "http"
  preset: balanced
  username: "admin"
  password: "admin"

processors:
  - add_host_metadata: ~
  - add_cloud_metadata: ~
  - add_docker_metadata: ~
  - add_kubernetes_metadata: ~


monitoring.enabled: false

Check the compatibility matrix for metricbeat OSS and Opensearch. A similar discussion is here.

Make sure that

1. Both metricbeat and elasticsearch at the same version.

2. Both beat and ES is on OSS version.