edd_add_email_tag()

The edd_add_email_tag() function allows you to register custom email tags for purchase receipts and admin sale notifications and takes three parameters:

• $tag – The tag to register, such as “admin_email”. In the email settings, tags are wrapped with {} but not when they are registered.
• $description – A description of what the tag displays.
• $func – The call back function to render the tag’s output.

Here’s an example snippet that you can use and extend as needed: https://library.wpcode.com/snippet/j578kp2g/