Elasticsearch nodejs client update function

Hi
I am using elastic-search java script client
while i am writing a simple update command i am getting an error

 const EsResponse = await esClient.update({
      id: "dfsfsdfd213123XFTFG",
      index: "test",
      type: "_doc",
      body: { doc: { name: "update" } }
    });

The response error is

{
    "msg": "[invalid_type_name_exception] Document mapping type name can't start with '_', found: [_update]",
    "path": "/test/_update/dfsfsdfd213123XFTFG",
    "query": {
        "type": "_doc"
    },
    "body": "{\"doc\":{\"name\":\"update\"}}",
    "statusCode": 400,
    "response": "{\"error\":{\"root_cause\":[{\"type\":\"invalid_type_name_exception\",\"reason\":\"Document mapping type name can't start with '_', found: [_update]\"}],\"type\":\"invalid_type_name_exception\",\"reason\":\"Document mapping type name can't start with '_', found: [_update]\"},\"status\":400}"
}

I am using elasticsearch of version 6.3 can anyone help