SKU stands for stock-keeping unit which is a unique identifier that represents each purchasable item in your campaign.
Identifying your product with a SKU allows it to be tracked for inventory purposes.
By identifying every product in your project, you can minimize future conflicts with your fulfillment.
When setting up each product, you can add a SKU here:
When adding variants to your product, such as size or color, the system will populate all available combinations. You can add SKUs for each variation: