<system.webServer>
    <httpProtocol>
     <customHeaders>
       <add name="Access-Control-Allow-Origin" value="*" />
       <add name="Access-Control-Allow-Methods" value="POST" />
       <add name="Access-Control-Allow-Headers" value="content-type" />
     </customHeaders>
   </httpProtocol>
  </system.webServer>