Logout from amember with another site

I have the following logout script for amember:

Code:

<?php
require_once('https://aMemberSite.com/config.inc.php');
setcookie('_amember_ru', '', time() - 3600 * 26, '/');
setcookie('_amember_rp', '', time() - 3600 * 26, '/');
$to_delete = array();

plugin_after_logout($_SESSION['_amember_user']);

foreach ($_SESSION as $k=>$v){
   if (!preg_match('/^_amember/', $k) || $k == '_amember_login_attempt_id') continue;
   $to_delete[] = $k;
}

foreach ($to_delete as $k){
   if (ini_get('register_globals'))
       session_unregister($k);
   else
       unset($_SESSION[$k]);
   unset($$k);
}


session_write_close();
if (!$config['protect']['php_include']['redirect'])
    @($config['protect']['php_include']['redirect'] = 
        'http://' . $_SERVER['HTTP_HOST'] . '/'); 
        
?>

The script is stored in a PHP file on the aMemberSite.com (https://amembersite.com/customlogout.php). After i access it and return to the Member page i see that i am logged out. That's great. When i try to execute the "customlogout.php" script that is described above from another site like: https://aMemberSite2.com/customlogout.php the logout doesn't work. I think the problem is with the session information. What can i do to have it working ?