WP Travel Pro provides you the feature of making payment in multiple installments.. You can add any number of installments to be made by customer and set any percentage(%) of amount to be paid as per your requirement in multiple installments. But the remaining payment should be made through user dashboard.
Also, the feature of making payment in multiple installments has been provided for individual trip. You can use global set up for installment process for all trips as well as can use your own set up for individual trip.
You can set your own setup(custom setup) regarding multiple installments for individual trip by going to Admin Panel > Trips > Individual trip (edit trip) > Dates and Prices
If you have any confusion then please post them in our official support forum.