I am not sure where you are trying to do this and how but https://www.wikidata.org/wiki/Special:GoToLinkedPage%5Bhttps://www.wikidata....] might be useful. You can call it with an item ID and a wiki code in the URL and it will redirect you to the article on that wiki.
Thanks Lydia. I was trying to retrieve the wikipedia page from the RDF dump. "schema:about" seems to be the right property.