Mandate POS customer
Customer information helps you to sell more. The more you know about them and their needs, the easier it is to identify opportunities to sell them new products and target them with appropriate offers. Profiling existing customers also makes it easier to find new ones. You can look for similar prospects, and sell to them in a similar way. For that we made customer as mandatory in POS. Using this app we can profile all the customers who are coming and going every day.
POS Screen
Enable "Is Customer Required" in Point of Sale --> Configuration --> Point of Sale.

If customer is not selected then popup will show.