Some suggestions:

To complete the above situation, the cashier system must first support it.

The first type is usually called leaving an order, and the conditions are: : When two or more people are consuming, the customer who left first and the customers present recognize each other. What we have to do is to ask the service staff to fill in the reservation slip and have the customers in the site sign for confirmation. (That is, promising to pay for the customer who left)

In the second minute, the customer who left first has to pay for his friend. The cashier operation merges the bills and pays them together. However, it should be noted that the customer who has purchased The hand number of the order is shown as settled in the field, so consumption cannot continue. If you want to continue consumption, you must leave the card blank, so that no more money will be generated.

Hope it helps, welcome to communicate!