PHP facebook 登录无法从用户那里获取电子邮件

我正在使用代码通过Facebook登录并获取包括电子邮件在内的用户信息..它在大多数情况下都有效，但我无法在我的数组中获取电子邮件...

这是我的代码：

<?php
session_start(); //Session should always be active
$app_id             = 'appID';  //localhost
$app_secret         = 'secret';
$required_scope     = 'public_profile, publish_actions, email'; //Permissions required
$redirect_url       = 'URL'; //FB redirects to this page with a code
require_once __DIR__ . "/facebook-php-sdk-v4-4.0-dev/autoload.php"; //include autoload from SDK folder
//import required class to the current scope
use Facebook'FacebookSession;
use Facebook'FacebookRequest;
use Facebook'GraphUser;
use Facebook'FacebookRedirectLoginHelper;
FacebookSession::setDefaultApplication($app_id , $app_secret);
$helper = new FacebookRedirectLoginHelper($redirect_url);
try {
  $session = $helper->getSessionFromRedirect();
} catch(FacebookRequestException $ex) {
    die(" Error : " . $ex->getMessage());
} catch('Exception $ex) {
    die(" Error : " . $ex->getMessage());
}

if ($session){      
    $user_profile = (new FacebookRequest($session, 'GET', '/me'))->execute()->getGraphObject(GraphUser::className());

    //save session var as array
    $_SESSION["fb_user_details"] = $user_profile->asArray(); 
    $user_id = ( isset( $_SESSION["fb_user_details"]["id"] ) )? $_SESSION["fb_user_details"]["id"] : "";
    $user_name = ( isset( $_SESSION["fb_user_details"]["name"] ) )? $_SESSION["fb_user_details"]["name"] : "";
    $user_email = ( isset( $_SESSION["fb_user_details"]["email"] ) )? $_SESSION["fb_user_details"]["email"] : "";
if(isset($_SESSION["fb_user_details"]))
    {
        print 'Hi '.$_SESSION["fb_user_details"]["name"].' you are logged in! [ <a href="?log-out=1">log-out</a> ] ';
        print '<pre>';
        print_r($_SESSION["fb_user_details"]);
        print '</pre>';
    }

}else{ 
    echo "we dont have a session";
    //session var is still there
    if(isset($_SESSION["fb_user_details"]))
    {
        print 'Hi '.$_SESSION["fb_user_details"]["name"].' you are logged in! [ <a href="?log-out=1">log-out</a> ] ';
        print '<pre>';
        print_r($_SESSION["fb_user_details"]);
        print '</pre>';
    }
    else
    {
        //display login url 
        $login_url = $helper->getLoginUrl( array( 'scope' => $required_scope ) );
        echo '<a href="'.$login_url.'">Login with Facebook</a>'; 
    }
}

我的结果是这样的：

Array
(
[id] => 
[first_name] => 
[gender] =>
[last_name] => 
[link] => 
[locale] => 
[name] => 
[timezone] => 
[updated_time] => 
[verified] => 
)

我的阵列中没有电子邮件？任何想法为什么？

我也尝试添加这个

$user_profile->getProperty("email");

在此行之后

$user_profile = (new FacebookRequest($session, 'GET', '/me'))->execute()->getGraphObject(GraphUser::className());

并且仍然注意到... 我的许可似乎没问题...