Must have apps & discount in combination with payment gateway?

Hello SI Team

Reading the documentation here:

https://stackideas.com/docs/payplans/administrators/quick-solutions/must-have-apps-in-payplans

I am wondering how does this work in combination with a payment gateway such as Fast Spring.

At the Fast Spring end there is a fixed price.

And of course you can apply discount codes in the Fast Spring Pop up Store.

But what I do not get is lets say I have a discount App such as the Social one.

A user does some sharing on Social Media and gets eg a 10% discount.

Does this get passed through to Fast Spring?

How/Does Fast Spring even know about this discount? Be told about this discount?

Does this make sense?

thanks

Paul