Is it possible in Wordpress to generate a pdf with a unique code upon purchase and send it to the buyer?

Question

PDF

When I sell a virtual product from the Woocommerce system on wordpress, is it possible to do something so that a unique code is automatically generated, inserted into a pdf file and sent to the client?
The bottom line is that I sell certificates and they need to be somehow protected from copying, so that there would be a unique code and I could check that the person really paid for the certificate.
Has anyone done this, please help.