Question about Unique identifier

Select a template field to be used as the unique identifier for each record.

So with Product Fields:

Product Name:

Description:

…

Product URL:

So I just need to input \” Product URL\”  , click \”Create \”Product URL\” in the Unique identifier ? (as attached image)

The product Fields are not in list of drop down in Unique identifier, it only has pots_name ; post_title; post_content; post_status (can cause user unsure if the unique indentifier is correct or not. (as image attached)