I'd tried to look at advanced configuration settings https://www.mediawiki.org/wiki/Wikibase/Installation/Advanced_configuration#Optional_settings_2 , but the link there to https://phabricator.wikimedia.org//r/p/mediawiki/extensions/Wikibase;browse/master/docs/options.wiki looks broken and I don't know enough to reconstruct it :-(

Regards, 

Victor Agroskin