provisional headers are shown
header("Access-Control-Allow-Origin: *"); header('Access-Control-Allow-Origin: *'); header('Access-Control-Allow-Methods: POST, GET, OPTIONS'); header('Access-Control-Allow-Headers: *'); header('Access-Control-Max-Age: 1728000'); header("Content-Length: 0"); header("Content-Type: text/plain"); //add this on the server side // on the top of the file