Benim çalışan örneğim şu şekilde:

$response->header("Access-Control-Allow-Origin", "http://localhost:8000");
$response->header("Access-Control-Allow-Headers", "Cache-Control, Pragma, Origin, Authorization, Content-Type, X-Requested-With");
$response->header("Access-Control-Allow-Methods", "GET, PUT, POST, OPTIONS, DELETE");