How do I add a gift certificate to an existing booking?

It is common to enter a gift card code when creating a reservation. Both in the admin panel and on the customer page, input fields are available for this. Adding a gift card code to a reservation afterward is possible via the front end of the application. This function can be accessed by adding the following to the i-Reserve domain name: /front.php?mod=giftentry

https://www.organization.i-reserve.net/front.php?mod=giftentry