Alter packing slip item quantity using WooCommerce PDF Invoices, Packing Slips, Delivery Notes and Shipping Labels plugin

functions.php

add_filter('wf_pklist_alter_package_item_quantiy', 'alter_packing_slip_quantiy', 10 , 5);
function alter_packing_slip_quantiy($item_quantity, $template_type, $_product, $item, $order)
{   
    if($template_type=='packinglist')
    {
        if($item_quantity>1)
        {
            $item_quantity = '<span style="color:red;">'.$item_quantity.'</span>';
        }
    }
    return $item_quantity;
}