I have a Wordpress website with eCommerce using cart66.
Cart66 by default integrates with Australia Post live shipping rates: [url removed, login to view]
[url removed, login to view]
I needed to integrate it with Fastway couriers and it was done successfully. From the frontend it calculates the rates and we can checkout successfully. However, Australia post does not work, we want both of them to work simultaneously.
The exact requirements and use case scenario is pasted here - [url removed, login to view]
This needs to be fixed urgently. Let me know if you have the skills and are up to the job.