BigCommerce doesn't natively support the sending of Commodity information, but this can be set up using Custom Fields.
Add Custom Fields In BigCommerce
BigCommerce have a guide on what Custom Fields are and how to add them to your products here: Custom Fields Guide.
Add the fields in Shiptheory
Once you have added these fields in BigCommerce, Shiptheory needs to know where to look to find the new data. To add this, navigate to your BigCommerce settings page in Shiptheory, by clicking Channels > BigCommerce and then clicking Advanced settings at the bottom of the page.
From here you can enter the field names you used in BigCommerce into Shipthory.
BigCommerce:
Shiptheory:
Now when those fields are filled in, we will receive the data with each shipment. If you need any assistance please don't hesitate to get in touch with us at support@shiptheory.com or +44 117 403 4313.