You can set up to automatically generate invoices based on your billing cycle.
Navigate to Invoices > Invoice Scheduler
1. First, select which appointments do you want to invoice. Only the completed ones or both completed and assigned
2. Next set the schedule. You can select the invoices to run weekly/bi-weekly on a given day or monthly on a particular date
3. You have the option to process payments for invoice also after specified number of days from invoice creation