How to get Email id from FB library – Facebook api

I want to access email id of the user, for that i tried below code, I checked many sites for this purpose. I found these ways to access user’s email id. But none of them seems to work. Please help me to solve this problem.

Thanks in advance.

<?php

session_start();
require_once 'autoload.php';

use FacebookFacebookSession;
use FacebookFacebookRedirectLoginHelper;
use FacebookFacebookRequest;
use FacebookFacebookResponse;
use FacebookFacebookSDKException;
use FacebookFacebookRequestException;
use FacebookFacebookAuthorizationException;
use FacebookGraphObject;
use FacebookEntitiesAccessToken;
use FacebookHttpClientsFacebookCurlHttpClient;
use FacebookHttpClientsFacebookHttpable;

// init app with app id and secret
FacebookSession::setDefaultApplication('MY_app_id', 'my_app_secret');
$helper = new FacebookRedirectLoginHelper('http://prov.resolv.com/provision_sid/Facebook_2/fbconfig.php');
try {
    $session = $helper->getSessionFromRedirect();
} catch (FacebookRequestException $ex) {
} catch (Exception $ex) {
}

if (isset($session)) {
    // graph api request for user data
    $request = new FacebookRequest($session, 'GET', '/me');
    $response = $request->execute();
    // get response
    $graphObject = $response->getGraphObject();
    $fbid = $graphObject->getProperty('id');              // To Get Facebook ID
    $fbfullname = $graphObject->getProperty('name');      // To Get Facebook full name
    echo $femail = $graphObject->getProperty('email'); 

    die();

    $_SESSION['FBID'] = $fbid;
    $_SESSION['FULLNAME'] = $fbfullname;
    $_SESSION['EMAIL'] = $femail;
    /* ---- header location after session ---- */


    header("Location: index.php");
} else {
    $loginUrl = $helper->getLoginUrl();
    header("Location: " . $loginUrl);
}
?>

I tried multiple option to request email id

1> $request = new FacebookRequest($session, 'GET', '/me?fields=name,email');

2> $request = new FacebookRequest($session, 'GET', '/me',['fields' => 'id,name,email,address,first_name,last_name']);

By above request too, I’m not able to get email id of the user.

Is there any other way to request email id of the user.