Hide express paid shipping options when stock of the product is 0 or less than 0 (backorder cases) in Wocommerce checkout - wordpress

Question

I set 2 methods of delivery:
Express shipping 48 hours at a cost which es a % of the total cart $ amount
Normal Free shipping in 29 days
The functionality that I want is the following:
If the stock of the product is = 0 or less than 0 (backorder is allowed), the Express shipping option should be hidden. Just must show the Normal free shipping option.
If the stock of the product is >0, both options should be shown.
If I selected more than one product, and one or more of the products does not have stock, the Express shipping option also should be hidden.
From another answer related to this question, I tried the script showed in the answer.
The problem is the following: in the last part of the script there is a mention to a variable in an external plugin.
How I adapt the code to a more generic woocommerce without that plugin?
Script:
/* !Hide Shipping Options Woocommerce */
add_filter( 'woocommerce_available_shipping_methods', 'hide_shipping_based_on_quantity' , 10, 1 );
function check_cart_for_oos() {
// load the contents of the cart into an array.
global $woocommerce;
$found = false;
foreach ( $woocommerce->cart->get_cart() as $cart_item_key => $values ) {
$_product = $values['data'];
$_product_quantity = $_product->get_stock_quantity();
$_cart_quantity = $values['quantity'];
if (($_product_quantity <= 0) || ($_cart_quantity > $_product_quantity)) {
$found = true;
break;
}
}
return $found;
}
function hide_shipping_based_on_quantity( $available_methods ) {
// use the function check_cart_for_oos() to check the cart for products with 0 stock.
if ( check_cart_for_oos() ) {
// remove the rate you want
unset( $available_methods['table_rate_shipping_next-day'] ); // Replace "table_rate_shipping_next-day" with "table_rate_shipping_your-identifier".
}
// return the available methods without the one you unset.
return $available_methods;
}
From: Remove next day shipping method for out of stock items in Woocommerce

Answer 1

In that answer, it's already mentioned to use your own shipping method identifier. So you just need to replace the shipping method identifier with yours.
// use the function check_cart_for_oos() to check the cart for products with 0 stock.
if ( check_cart_for_oos() ) {
// remove the rate you want
unset( $available_methods['USE_YOUR_OWN_IDENTIFIER_HERE'] ); // Replace "table_rate_shipping_next-day" with "table_rate_shipping_your-identifier".
}