For some reason it is hidden. This is from your checkout page source:
<form class="checkout_coupon woocommerce-form-coupon" method="post" style="display:none">
PS: Your StoreFront theme is out-of-date. Try updating to the newest version.
Sir,
Now storefront theme updated but there does not showing coupon code successful or unsuccessful message. And what can I do to show the coupon code box on the checkout page?
Please guide me. Thanks.
@masurana The below appears to be in the Additional CSS section of your customizer, which is causing all notices to be hidden, and it also hides the coupon field in the checkout page:
.woocommerce-error, .woocommerce-info, .woocommerce-message, .woocommerce-noreviews, p.no-comments {
display: none;
}
Once this is removed, you will be able to see notices again.