Trigger quantity update on changing variant

Trigger quantity update on changing variant

add_filter('woocommerce_after_add_to_cart_form', function (){
    ?>
    <script>
        jQuery( document ).ready( function() {
            jQuery( ".single_variation_wrap" ).on( "show_variation", function ( event, variation, purchasable ) {
                jQuery(this).closest('form').find('input[name="quantity"]').trigger('change');
            });
            jQuery('input[name="quantity"]').trigger('change');
        });
    </script>
<?php
}, 10);