如何使用多个axios标头

我正在开发本机应用程序。该项目使用FatSecret REST API。该API使用OAuth 2.0身份验证。首先，我收到访问令牌。我尝试使用令牌接收数据，但出现错误。发送帖子后，我的状态码为200，但我不明白。

    let form = new FormData();

    var headers = new Headers();
    headers.append("content-type", "application/json"),
      headers.append(
        "Authorization",
        "Basic " +
          base64.encode(
            <clientID>:<clientSecret>,
          ),
      ),
      form.append("grant_type", "client_credentials");
    form.append("scope", "basic");

    fetch("", {
      method: "POST",
      headers: headers,
      body: form,
    })
      .then(res => res.json())
      .then(json =>{this.calc(json.access_token)})


  };

//------------------------------------------------------
//success (get Access token)
//--------------------------------------------------------

  calc =(token)=>{  
    console.log(token)

    var headers2 = new Headers();
    headers2.append("Content-Type", "application/json");
    headers2.append(
      "Authorization",
      "Bearer "+token),

    fetch(".api",{
      method :"POST",
      headers:headers2,
      body:"method=foods.search&search_expression=toast&format=xml"
    }).then(res=>console.log(res));
}

Response {type: "default", status: 200, ok: true, statusText: undefined, headers: Headers, …}
headers: Headers {map: {…}}
ok: true
status: 200
statusText: undefined
type: "default"
url: ".api"
_bodyBlob: Blob {_data: {…}}
_bodyInit: Blob {_data: {…}}
__proto__: Object

您可以将以下代码用于带有axios的多个标头：

const instance = axios.create();
      instance.defaults.headersmon['Accesstoken'] = 'Bearer '+token;

      const response = await instance.post(<api url>, {
        id: orderId
      });