For walk in customers there would be separate option for creating ticket and invoice
For walk in customers, there should be separate option that directly create ticket with timer in no time and no email should be necessary . Kindly do this as ticket system is basically for mail in customers and customers through email. There should be separate system for walk in customers so no time would be taken.
The walk-in customer is really only intended for people that don’t want to leave their name. You should be able to create customers for walk-ins that only want to leave a phone number currently.