Spakpost tracking integration

Your software
My Mautic version is: 4.1.2
My PHP version is: 7.4

Your problem
My problem is: We are using Spakpost API to send emails via Mautic.
Everything is working fine but Sparkpost Click Tracking is not working for Mautic. They sent me this: Getting Started with Engagement Tracking but I am not sure about how to get this going with Mautic. Does anyone have experience with this and can perhaps point me into the right direction?
Thank you very much.

These errors are showing in the log:

Steps I have tried to fix the problem: