WordPress x aMember Shopping Cart information

Hello, I'm trying to show some aMember Shopping Cart information on my WordPress Theme with the following code:

<?php
require_once 'server/paht/to/amember/library/Am/Lite.php';
require_once 'server/paht/to/amember/bootstrap.php';
?>
...
<?php
$cart = Am_Di::getInstance()->session->cart;
if($cart && $cart->getItems()){
echo 'Your cart has ' . count($cart->getItems()) . ' item(s)';
}
?>
... and I'm getting the error below:

Script Error​

An internal error happened in the script, ​

Can you please help or point me in the right direction? Thank you!

Any suggestion?