Setting/automailpendpaytype
Select on what the payment is calculated.
"Percent of Balance Due" - will use the 'Balance Due' in the Charges & Payments tab of the booking.
"Percent of Charges" - will use the 'Total Charges' in the Charges & Payments tab of the booking
"Percent of Price" - will use the value in the 'Price' field in the Charges & Payments tab of the booking.
"Percent of Base Value" - will use the first row value (room charges) in the Charges & Payments tab of the booking. (Please note: if the room charge was automatically added at the time of the booking, will not work if the charge was manually added to the booking).
"One Night of Charges" - will use the average price of a night calculated from the sum over all nights.