Loyalty Points UX Flow

Problem: When I go to a restaurant, I want to collect loyalty points on the money I spend, so I can get free meals for being a frequent customer.

Solution:
As and when the user purchases food from the restaurant, they can scan the invoice QR Code using the restaurant app. I have introduced a gamification concept. If the QR Code is valid, The cup will be filled with the drops. The number of drops can be calculated based on the amount that the user had purchased. When the cup has filled completely, it will be ready for purchasing with the discount.