Selling Digital Product: Coupon

Dear Sir/Madam,

I want to sell coupon, I think digital product is the correct product I do. As coupon should have coupon code printed on the coupon, I have an engine to print code on image for download.

How can I pass the quantity to my engine and provide the download link with the invoice id to my customer who bought the coupon product? Customer can go to my coupon server and download it?

I search via the forums but no one ask for this question. Please help.

Best regards,

Kelvin.

Hire someone to perform this modification for you. Unfortunately, CS-Cart does not have such functionality out of the box