$oAuth2Client = $FB->getOAuth2Client();
if (!$accessToken->isLongLived())
    $accessToken = $oAuth2Client->getLongLivedAccessToken($accessToken);

$response = $FB->get("/me?fields=id, first_name, last_name, email,user_birthday, picture.type(large)", $accessToken);
$userData = $response->getGraphNode()->asArray();
$_SESSION['userData'] = $userData;
$_SESSION['access_token'] = (string) $accessToken;
header('Location: index.php');
exit();

if (isset($_SESSION['access_token'])) {
    header('Location: index.php');
    exit();
}

$redirectURL = "http://localhost:8080/tom/fb-callback.php";
$permissions = ['email','user_birthday'];
$loginURL = $helper->getLoginUrl($redirectURL, $permissions);
?>

Fatal error: Uncaught FacebookExceptionsFacebookAuthenticationException: (#100) Tried accessing nonexisting field (user_birthday) on node type (User) in C:xampphtdocstomFacebookExceptionsFacebookResponseException.php:106 Stack trace: #0 C:xampphtdocstomFacebookFacebookResponse.php(210): FacebookExceptionsFacebookResponseException::create(Object(FacebookFacebookResponse))
#1 C:xampphtdocstomFacebookFacebookResponse.php(255): FacebookFacebookResponse->makeException() #2 C:xampphtdocstomFacebookFacebookResponse.php(82): FacebookFacebookResponse->decodeBody() #3 C:xampphtdocstomFacebookFacebookClient.php(224): FacebookFacebookResponse->__construct(Object(FacebookFacebookRequest), '{"error":{"mess...', 400, Array) #4 C:xampphtdocstomFacebookFacebook.php(469): FacebookFacebookClient->sendRequest(Object(FacebookFacebookRequest))
#5 C:xampphtdocstomFacebookFacebook.php(341): FacebookFacebook->sendRequest('GET', '/me?fields=id, ...', Array, Object(FacebookAuthenticationAccessToken) in C:xampphtdocstomFacebookExceptionsFacebookResponseException.php on line 106