Hook to add some logic after a user pays?

Hi there!
I am wondering if this plugin could be useful for a project.
it seems having everything I need, but one very important requirement is that there is a way to hook into the plugin functionalities, so that after a user has successfully paid, the plugin is not only giving them access, but also setting up a few cron jobs which will send them some emails (containing the links to the content they got access to).

I am a developer and I know how to code the scheduling part, I just need to know if there are hooks/filters which would allow me to build up a functionality like the above.
or if there is another way you could suggest to achieve it.

thank you in advance!