Step 1:
Inside NetSuite, from the top navigation pane, please go to the Lists > Accounting > and click on the Shipping Items. Below is a screenshot to help you understand this visually.
Step 2:
COPY that shipping method internal ID which you want to map between your NetSuite account and the BigCommerce store. Below is a screenshot to help you understand this visually.
Step 3:
Inside the BigCommerce NetSuite Integrator, please go to the Configuration Page > App Settings
> and scroll-down to this "BigCommerce Shipping Speed:" setting, further click on the Configure button. Post-pop-up, enter these BigCommerce shipping method's corresponding NetSuite Internal IDs in the empty fields, and hit the Save button. Below are two screenshots to help you understand this visually.
Step 4:
Hit the Save button from the bottom of this App Settings section inside our BigCommerce NetSuite Integrator.
Congratulations, you have successfully
mapped a BigCommerce shipping method with its respective NetSuite shipping method using the BigCommerce NetSuite Integrator.