title: Preflight request is sent with all methods
body: <p>My FE application is using API from different domain. I know that it should trigger CORS, but as I understood it shouldn't create preflight for every request.</p>
  
  <p>According to <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS" rel="noreferrer">docs</a>, I shouldn't have preflight request for <code>GET</code> method.</p>
  
  <pre><code> Cross-site requests are preflighted like this since they may have implications to 
   user data. In particular, a request is preflighted if:
  
      - It uses methods other than GET, HEAD or POST. 
  Also, if POST is used to send request data with a Content-Type 
  other than application/x-www-form-urlencoded, multipart/form-data, 
  or text/plain, e.g. if the POST request sends an XML payload to the
  server using application/xml or text/xml, then the request is preflighted.
      - It sets custom headers in the request 
  (e.g. the request uses a header such as X-PINGOTHER)
  </code></pre>
  
  <p>However, every request that I'm sending, has preflight (OPTIONS) request, no matter if it's GET or POST, and I find it strange (according to what docs said). </p>
  
  <p>I set some headers (and I'm sending it with <code>withCredentials: true</code>), but I don't see that it should be the issue:</p>
  
  <pre><code>  headers.append('Access-Control-Allow-Origin', FRONTEND_URL);
    headers.append('Accept', 'application/json');
    headers.append('Content-Type', 'application/json');
    headers.append('Authorization', this._generateApiKey());
    headers.append('Language', this._languageISOCode);
  </code></pre>
  
  <p>Am I missing something?</p>