Add custom variable to cart content [closed]

I had to do something similar a while ago, this is what was working for me:

In the example, the custom input name is “test_field” inside the add to cart form, and this way when you dump the cart_contents, you can see the value somewhere at the end

//Store the custom field
add_filter( 'woocommerce_add_cart_item_data', 'add_cart_item_custom_data_vase', 10, 2 );
function add_cart_item_custom_data_vase( $cart_item_meta, $product_id ) {
  global $woocommerce;
  $cart_item_meta['test_field'] = $_POST['test_field'];
  return $cart_item_meta; 
}

//Get it from the session and add it to the cart variable
function get_cart_items_from_session( $item, $values, $key ) {
    if ( array_key_exists( 'test_field', $values ) )
        $item[ 'mmCentre' ] = $values['test_field'];
    return $item;
}
add_filter( 'woocommerce_get_cart_item_from_session', 'get_cart_items_from_session', 1, 3 );