This snippet sends by email the list of coupons used in an order. You can customize the “$to” variable and define your own email address, and the “$message” to have your own text.
Add this code to your child theme’s functions.php file or via a plugin that allows custom functions to be added, such as the Code snippets plugin. Avoid adding custom code directly to your parent theme’s functions.php file, as this will be wiped entirely when you update the theme.
https://gist.github.com/woogists/76dc25206a08d18338a2b4dc5be192be