exporting simple products, parent and variable

I’m trying to export all products to other website. Original website has simple and variable products. I’m exporting products with wp all export, in wp all import I chose variable product type(if no variations then create simple product option is checked). Following this tutorial:

https://www.wpallimport.com/documentation/how-to-export-woocommerce-variable-products-csv-xml/

Variable products should have Parent SKU. But there’s no such option. There’s only Parent ID. In WP all Import I can’t use option

All my variable products have SKUs or some other unique identifier. Each variation is linked to its parent with its parent's SKU or other unique identifier.

because all, simple and variable products, including parent, have unique SKU and variable products don’t have any information regarding parents sku.