Gadget export
To export the Navigation_popups gadget, click on "Download" button, save the downloaded file, go to Special:Import on the destination wiki and upload it. Then add the following to MediaWiki:Gadgets-definition page:
* Navigation_popups [ResourceLoader |dependencies=mediawiki.api, mediawiki.user, mediawiki.util, user.options, mediawiki.jqueryMsg |type=general] |popups.js |navpop.css
You must have appropriate permissions on the destination wiki (including the right to edit system messages) and import from file uploads must be enabled.