Connecting an external affiliate program to marketpress

Hi,

First let me just say I appreciate all the support. I feel a bit like the problem child always asking something LOL.

Since Affiliate isn't working with marketpress- I'm exploring other options for an affiliate plugin. Since I want to use marketpress as my shopping cart - I found this tutorial for hooking WP Affilliate into another cart system

The how to is here:

https://www.tipsandtricks-hq.com/wordpress-affiliate/api-awarding-commission-via-wordpress-hook-501

Do you have any guidance on how I get the order total & hook this in?

Thanks in advance.