How do I add product costs?

Open Products, click a variant, and set its unit cost and the date it takes effect. Where Shopify already holds an inventory cost, nouz prefills it and marks it as coming from Shopify; anything you type is yours and a sync will never overwrite it.

Set the weight in the same panel. The shipping rate card needs it, and a variant without one is priced by a zone fallback and flagged. For a big catalogue, the product cost list template is the same format as a spreadsheet.