Mailgun API：请求标头字段Access-Control-Allow-Headers不允许授权-React

Question

如何设置我的ReactJs应用程序以防止出现以下错误消息：

访问CORI策略已阻止从源“ https://api.mailgun.net/v3/sandbox89eb8f83cebd77263172e.mailgun.org/messages”获取“ http://localhost:3002”的访问：在飞行前响应中，Access-Control-Allow-Headers不允许请求标头字段授权。

 onSubmitForm(e){
  e.preventDefault();
  //Mailgun

  var api_key = 'API Key(//obviously won't show this)'; 
  var domain = 'sandbox89eb814ff83bd77c0c7d263172e.mailgun.org';
  var mailgun = require('mailgun-js')({apiKey: api_key, domain: domain});

  var data = {
    from: 'Excited User <me@samples.mailgun.org>',
    to: 'test@something.org.au',
    subject: 'Hello',
    text: 'Testing some Mailgun awesomeness!', 
  };

  mailgun.messages().send(data, function (error, body) {
    console.log(body);
  });

  }