Do you want the JSON from Kibana ?
{
  "_index": "heartbeat-2019.06.26",
  "_type": "_doc",
  "_id": "9mXRk2sBZ5JtzLdILpq2",
  "_score": 1,
  "_source": {
    "url": {
      "full": "tcp://example.net:13000",
      "scheme": "tcp",
      "domain": "example.net",
      "port": 13000
    },
    "@timestamp": "2019-06-26T12:44:47.044Z",
    "host": {
      "os": {
        "kernel": "4.18.0-21-generic",
        "name": "Ubuntu",
        "platform": "ubuntu",
        "version": "18.04.2 LTS (Bionic Beaver)",
        "codename": "bionic",
        "family": "debian"
      },
      "name": "example",
      "id": "123699f28ff345a28ecf7cc208e6a543",
      "architecture": "x86_64",
      "containerized": false,
      "hostname": "example"
    },
    "resolve": {
      "rtt": {
        "us": 2375
      },
      "ip": "192.168.1.2"
    },
    "ecs": {
      "version": "1.0.0"
    },
    "monitor": {
      "name": "",
      "status": "up",
      "type": "tcp",
      "duration": {
        "us": 4186
      },
      "id": "auto-tcp-0X28C61C257AAC6812-530d2ef90fbce828",
      "check_group": "0a424351-9810-11e9-a811-00155de82c05",
      "ip": "192.168.1.2"
    },
    "portname": "port name",
    "event": {
      "dataset": "uptime"
    },
    "@version": "1",
    "tcp": {
      "rtt": {
        "connect": {
          "us": 1755
        }
      }
    },
    "tags": [
      "beats_input_raw_event"
    ],
    "agent": {
      "id": "ebcd1dd7-9ac3-4695-b470-3ed56228d332",
      "ephemeral_id": "23b63eff-e498-437c-b0a5-714759fb13f6",
      "hostname": "example",
      "type": "heartbeat",
      "version": "7.1.1"
    },
    "summary": {
      "down": 0,
      "up": 1
    }
  },
  "fields": {
    "@timestamp": [
      "2019-06-26T12:44:47.044Z"
    ]
  }
}