Answers for "add cors header doesnt work"

cors not working

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");