how to use extension subscrib or hook the payment status and shipment status changed?

[Weimmer]

Hi there,

I'm developing an extension for invoice generation and need to trigger it when the payment status changes to "paid." Additionally, I want to send a notification email to the customer when the shipment status changes to "shipped."

I've reviewed the documentation on hookable events and extensions but am unsure how they work. Is there a list of hookable functions available?

Any guidance would be greatly appreciated!

Best regards,
Weimmer