Some business owners asked for this feature, because there are some people who would always keep asking for coupon when they just see the field exist, so it is a good practice for the local business owner or store owner has the option to hide or unhide the coupon code field any time he/she wants and especially when running promotional campaigns in some occasions that buyers spend their money during these kinds of promotional campaigns then at the end of the promotional campaign the business owner or manager can hide the coupon code field on the checkout page.