Code-Snippets-Functions/Execute a function on a child site/WooCommerce/hide-free-shipping-when-specific-coupons-are-applied.txt

add_filter( 'woocommerce_package_rates', 'filter_woocommerce_package_rates', 10, 2 );
function filter_woocommerce_package_rates( $rates, $package ) {
    $targeted_coupons = array("544"); // Here set your related coupon codes

    $applied_coupons = WC()->cart->get_applied_coupons();

    if ( ! empty($applied_coupons) && array_intersect( $targeted_coupons, $applied_coupons ) ) {
        foreach ( $rates as $rate_key => $rate ) {
            if ( 'free_shipping' === $rate->method_id ) {
                unset($rates[$rate_key]);
            }
        }
    }
    return $rates;
}