Generate SKU:  Auto Generate the sku for variants according to format: Parent SKU - Variation 1 - Variation 2. For example, if there is a T-shirt (white, XL)  its parent sku is T-shirt,  therefore the sku we generated is T-shirt - white - XL.


When edit single product

fill out the parent SKU and click on Generate as below





When edit products in bulk

 fill out the parent SKU and click on Generate as below > Click on Save