In order to confirm that a gift card functionality is enabled, follow the given path or you can use the direct URL :
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 Gift Cards".
If the checkbox is checked, the gift card functionality is enabled or vice-versa. If somebody is enabling the gift card functionality, the associated app needs to be killed and restarted again. (Please find the screenshot below)