WP Travel Pro or WP Travel Partial Payment addon provides the feature of sending a reminder notification to the customer via email about the remaining partial payment to be paid before going to the trip.

You have to enable ‘Enable Remainder Notification option to send a reminder notification to the customer via email so that customer can be notified to make the remaining payment by going to Admin Panel > WP Travel > Settings > Email > Partial Payment Email Templates

For detail assistance regarding Remaining Partial Payment Reminder feature, please refer link of our official documentation.

If you have any confusion then please post them in our official support forum.