its is a woocommerce website which is quite simple. The problem is they have a shipping company’s API integrated into the website which has been hardcoded into the website in the child theme’s functions.php website. This API is going to be deprecated by the end of next month. The new code for the new API implementation is already done by the previous developer and he has left comments stating to commenting out the old API integration code and uncommenting new code to make it live. Can anyone please tell me which functions to comment out and which ones to uncomment?? The shipping API is
https://api.hunterexpress.com.au/doc/api.pdf.

Any help is appreciated and will be compensated if necessary

see the new API code and old API code in the attachments
https://drive.google.com/file/d/1mfMcfXmwD6Pr4g78NpnGNNNOXGOLRfFo/view?usp=sharing