The shipping template (or shipping group) is a field included in all of Amazon's latest upload category templates (https://support.farapp.com/hc/en-us/articles/217185657-Amazon-Flat-File-Templates). The field didn't exist in the older category templates. The process for getting this set up is:
1) Create the field in NetSuite, provide us with the field name/id, and populate it for your items in NetSuite. You need to make sure the values in NetSuite match exactly (case-sensitive) the shipping group names you've configured in Seller Central.
2) FarApp will migrate you to the latest version of your Amazon category templates if any of the templates we have set up for you don't have the shipping group field. For this, you'll want to send us the latest version of your templates as detailed in the article I referenced above.
3) Once we're done, you can test post a few items using the FarApp products dashboard (https://app.farapp.com/products) to ensure the shipping group is getting set properly in Amazon.
4) Once you've verified it, let us know to trigger a full refresh of your catalog (if desired).