WP Travel Pro plugin provides the feature of adding custom links for the Book Now button. You can redirect the page to any URL as per your requirement by going to Admin Panel > Trips > Individual Trip(edited) > Prices and Dates > Prices.
Also, if you want to add a custom form as per your requirement for Book Now button, you can add a custom form instead of a custom link by going to Admin Panel > Trips > Individual Trip(edited) > Prices and Dates > Prices.
For detail assistance regarding custom booking, please refer to our official documentation.
For more details regarding using the custom Booking option available in WP Travel Pro plugin, please watch the Youtube video:
Further, if you have any queries, please submit them to our Contact page.