You are building a loyalty program for a major snack producer. When customers buy a snack at any of 100 participating retailers the event is recorded in AzureEvent Hub. Each retailer is given a unique identifier that is used as the primary identifier for the loyalty program. Retailers must be able to be added or removed at any time. Retailers must only be able to record sales for themselves. You need to ensure that retailers can record sales. What should you do?