es.Create error :status: 400, failed: [mapper_parsing_exception], reason: failed to parse

[gif-gif]

es, err := elasticsearch.NewTypedClient(elasticsearch.Config{
		Addresses: []string{"http://127.0.0.1:9200"},
		Username:  "es",
		Password:  "123456",
	})

	if err != nil {
		golog.Error("Error creating elasticsearch:" + err.Error())
		return
	}

	document := struct {
		Name string `json:"name"`
	}{
		"go-elasticsearch",
	}
	b, _ := json.Marshal(document)
	str := string(b)
	golog.Debug("doc:" + str)

	res, err := es.Create("index1", "doc_id6").Document(str).Refresh(refresh.True).Do(context.Background())
	if err != nil {
		golog.Error("es.Create error :" + err.Error())
		return
	}

	golog.WithTag("elasticsearch").Info(res)

running error is : status: 400, failed: [mapper_parsing_exception], reason: failed to parse
Document func not surport json string? only go struct ? why ? thanks gays.