Hi there,
Thanks for reaching out. I’d be happy to help with your question.
It is possible to create a custom ticket message using PHP, but this may not be feasible to do on a ticket by ticket basis.
If you are using WooCommerce for your ecommerce and payment functionality, there may be a way to do this from that side of things. However, I do not know of anything specific to recommend.
If you’d like to try this with PHP, let me know and I’ll track down an example snippet to get you started.
Thanks,
Sky