To create an Invoice for a Patient you can select
Option 1 Create it when in the Scheduler (see Create an Invoice at Appointment time)
Option 2 Use the New Invoice wizard button which will help you locate or create a new patient file and enter items for the invoice.
Option 3 Use the Invoice manager button and create a New Invoice
The New Invoice Wizard will help you create the Invoice for the patient. it will request that you select a patient to invoice, assist you in selecting the items to bill and completing the invoice.