The accounts you're seeing (test000-000-010, test000-000-013, etc.) are auto generated accounts, each corresponding to a real customer placing a real order at a restaurant. The sequential naming format (test000-000-XXX) is simply the system generated username assigned at the moment of account creation. Customers always have the option to personalise their account with a username of their choice, but many are casual diners who simply scan, order, pay, and leave and don't necessarily care about their username