title: Cookies are not sending with Content-type: application/json
body: <p>I want to POST data using fetch API. To send cookies I use credentials: include. If i POST without any headers cookies are visible in request (but body is empty because of none header). When I add headers like in below cookies are not visible.</p>
  <pre><code>const data = {
      testKey: 'abc'
  };
  
  fetch(BACKEND_URL + '/coupons', {
      method: 'POST',
      headers: {
          'Content-Type': 'application/json'
      },
      credentials: 'include',
       body: JSON.stringify(data)
  });
  </code></pre>
  <p>setting headers on server:</p>
  <pre><code>app.use((req, res, next) =&gt; {
    res.setHeader('Access-Control-Allow-Origin', 'http://localhost:3000');
    res.setHeader('Access-Control-Allow-Credentials', 'true');
    res.setHeader(
      'Access-Control-Allow-Headers',
      'Origin, Access-Control-Allow-Headers, X-Requested-With, Content-Type, Accept , Authorization'
    );
    res.setHeader('Access-Control-Allow-Methods', 'GET,POST,PATCH,DELETE,OPTIONS');
    next();
  });
  </code></pre>