Now with version 4.2.4 of the WP Travel plugin, the Coupon code email tag is available.
If you have used the coupon code while buying the trips then adding the coupon code email tag in the email template will make your coupon code available in the email you received.
You need to add this tag by going to Admin Panel > WP Travel > Settings > Email
Coupon Code Email Tag:
Further, if you have any queries, please submit them to our Contact page.