Out of all the standard fields, check which field, holds this BigCommerce SKU. In our case, it is (Item Name / Number). Below is a screenshot to help you understand this visually. In your case, it could be different.
Inside the BigCommerce NetSuite Integrator, please go to the
Configuration Page >
App Settings > and scroll-down to this "Sync BigCommerce SKUs to NetSuite as" setting, further
select that field from the drop-down menu, that holds your BigCommerce SKU inside NetSuite, and hit the
Save button. Below is a screenshot to help you understand this visually.
Note: In our case, it is (Item Name / Number), as a result, we selected "itemid", if yours is UPC CODE, select "upccode" inside our integrator, else the appropriate option. If it is a Custom field, simply check the box, and enter its value inside the empty box.
Also, for inventory sync, please make sure to (select / map) inventory locations, so our integrator can update NetSuite's locations inventory to the selected BigCommerce locations. You can do this via "Inventory Location Mapping" section under the Configuration Page > App Settings > Select Inventory Location.