In order to identify that "Promotional Coupons" functionality is enabled, follow the mentioned path or you can use the direct URL :
Dashboard -->Whitelabel-->Mobile Configurations
Note: the business name will be the same as the "Slug Name" as mentioned on the Dashboard.
Under the "Extended Settings", you can find a checkbox named as "Enable Promotional Coupons". If the checkbox is checked, the promotional coupons functionality is enabled or vice-versa. If somebody is enabling the promotional coupons functionality, the associated app needs to be killed and restarted again.