How do I create a single item with variants in Printful?

Hello,
I would like to know, for example, when I import 3 t-shirts from printful, designed with different designs, in shopify I have 3 different items.
If I want to create a single item with variants, am I right to create other variants in a single product and add a different “SKU” to each variant, taken from the different versions created in printful?
Thank you