Free product in cart

Hello
For internal management reasons; I have to add a free product to the cart each time a customer buy a product.
This is done via :

function add_free_product_with_two_items() {

// Define the ID of the free product
$free_product_id = 20320; // Replace with your actual product ID

// Set the minimum number of products required to trigger the free gift
$minimum_product_count = 1;

// Retrieve cart items
$cart = WC()->cart->get_cart();

// Initialize variables
$non_free_product_count = 0;
$free_product_exists = false;

// Loop through each item in the cart
foreach ($cart as $cart_item) {
   
  // Check if the item is not the free product
     if (!isset($cart_item['custom_price'])) {
     
   // Count non-free products
         $non_free_product_count++;
     } else {
 
  // Check if the free product is already in the cart
 $free_product_exists = true;
     }
}

// If the conditions are met, add the free product to the cart
if ($non_free_product_count >= $minimum_product_count && !$free_product_exists) {
     WC()->cart->add_to_cart($free_product_id, 1, 0, array(), array('custom_price' => 0));
}

}

// Hook the function to the WooCommerce calculation

add_action('woocommerce_before_calculate_totals', 'add_free_product_with_two_items');

How to hide product and price and quantity from the cart?

Thank you