You can limit available seats for booking a trip using the WP Travel Pro plugin. WP Travel pro plugin provides the inventory option with which you can limit the seat (number of seats) for booking the trip.
You can enable the inventory option and set the number of seats by going to Admin Panel > Trips > Individual Trip(edited) > Inventory Options so that customers will be able to book the trip only for the limited seats.
limit the seat:
Note: This feature is now applicable in the case of Fixed Departure as well as Trip Duration.
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