title: Express.js response to Angular CORS Error
body: <p>I want Express server side redirect angular page.<br>
  I run express at localhost:3000<br>
  angular at localhost:4200<br>
  when Express redirect to Angular localhost:4200 <br>
  I always get error<br><br></p>
  
  <pre><code>Failed to load http://localhost:4200/login: Request header field Authorization is not allowed by Access-Control-Allow-Headers in preflight response.
  </code></pre>
  
  <p><br>
  how to let angular accept cors response?</p>