Customers can easily follow you in the app so they get a notification when you sell food!
If the customer clicks on the heart on your location in the customer app, and make sure to allow notifications for the Karma app, this is activated. A customer can follow how many places they want.
Note that only one notification is sent per day, when your sale starts. This means that your followers wont receive additional notifications if you would put more food on sale during the day.