When creating product Variants for a parent Product, each Variant can have a unique SKU defined for it.
To do so:
- Open the Shop Products Manager
- Click the Product Name of the parent Product whose Variant you wish to edit
- In the add/edit Product view, click the Variant tab
- Click the name of the Variant you wish to edit
- For SKU, enter the value for this Variant
- Click Save
- In the main add/edit Product View, click Save