Needed when several articles in the other system are variants of the same product, for example sizes or colours of one T-shirt, and should be grouped under one product in Shopify.
To find the right Shopify product for a variant, Junipeer saves an ID in a product metafield. Choose which metafield to use here.
The ID saved is the parent ID from the other system when there is one, otherwise the article ID.
Requirements for the metafield
It must be a product metafield of type ID.
It must be filterable in the Shopify Admin API.
Good to know
If the list says There are no values available, either the Shopify connection isn't set up yet, or your shop has no metafield that meets the requirements. Create one in Shopify first, then come back and select it.
You can leave this empty if you don't group variants under one product.