Nascodere valore get app facebook

[Tecnologiamiky]

Ho un app di facebook che mi da il seguente indirizzo

https://apps.facebook.com/il_quiz/pag.php?code=AQCgp3ICNgzWSSen8y6DkeZg6_v2lWFv4qgbRolPqToGc0ayKAFOsNJCq6gz6ptGK832NJ4qJp1AqAooLq0VscFxpPOh85tBM8nwzlpEbKDFdGSYgDdBzkWiOro3CGigYIQtOtLCMMUcTFi5gWLMVrk6nonQrB62uvj1Vs4_jMeUUBFjxPZH_jnp9mgMvivqdkw#_=_

lo vorrei nascondere ma non so come, il codice che è questo

$app_id = 'xxxxxxx'; 
$app_secret = 'yyyyyyy'; 
$my_url = 'https://apps.facebook.com/zzzzz'; 
session_start(); 
$code = $_REQUEST["code"]; 
$token_url = "https://graph.facebook.com/oauth/access_token?" . "client_id=" . $app_id . "&redirect_uri=" . urlencode($my_url) . "&client_secret=" . $app_secret . "&code=" . $code; 

$response = file_get_contents($token_url); 
$params = null; parse_str($response, $params); 
$graph_url = "https://graph.facebook.com/me?access_token=" . 
$params['access_token']; 
$user = json_decode(file_get_contents($graph_url)); 
echo("Hello " . $user->name);