Generate License Files after Purchase

[spacelord_xan]

Hello,

I have the following requirements:
The customer should get an email with a license file for every product he purchased.

I am not searching for a solution how to generate license files, but I want to know how to integrate this into virtuemart.

My first approach was to write a shipment plugin, but I got stuck at the point when to generate the license.
Is there any method in the vmPSPlugin class that gets called after the product was successfully purchased, so I can generate a license file?

Maybe writing a shipment plugin is not the right approach?

It would be great if anyone could help me with this problem.

greetings,
xan