How to implement an informer on each product page, N rubles left before free delivery?

Question

PHP

We need to create an informer that displays the difference between the amount in the cart and the minimum order amount for free shipping. I am not strong in PHP.
Initial conditions: the minimum order amount is 1500 rubles, at which free shipping is included, this is already working by default. But I need that when a user adds a product to the cart, he sees on any page or in the header (this is not so important) how much more he needs to add to display the notification "Bonus: free shipping!".
Found the following code WC ()->cart->get_cart_subtotal () - displays the sum of all added goods to the cart.
How to write 1500 - WC()->cart->get_cart_subtotal()?

Answer 1

$total = WC()->cart->get_cart_subtotal();
$min = 1500;
$difference = $min - intval($total);

if ($difference <= 0) {
    echo "Доставка бесплатная";
} else {
    echo "Для бесплатной доставки пополните корзину на $difference";
}