composer require anhskohbo/accountkit
Follow the instruction from: https://developers.facebook.com/docs/accountkit/webjs
Example "server.php"
<?php
require 'vendor/autoload.php';
use Anhskohbo\AccountKit\Config;
use Anhskohbo\AccountKit\Client;
$facebookAppID = "<facebook_app_id>";
$accountKitAppSecret = "<account_kit_api_version>";
$client = new Client(new Config($facebookAppID, $accountKitAppSecret));
$token = $client->getAccessToken($_POST['code']);
$user = $client->getUser($token);
var_dump($user);
var_dump($user->getPhoneNumber());