remve an order item if it's value has been discounted to 0

wooptpm_order_items_1.php

<?php

// The product ID must be changed and must match the specific product that you want to be removed

add_filter('wooptpm_order_items', function ($order_items, $order){

    foreach($order_items as $item_id => $item ){

        $product =  $item->get_product();
        if($product->get_id() === 14 && $item->get_total() == 0) unset($order_items[$item_id]);
    }

    return $order_items;
}, 2, 10);