Gadget export
To export the articlefeedback-core 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:
* articlefeedback-core[ResourceLoader|type=general|skins=vector|dependencies=mediawiki.api,ext.gadget.rsw-util,oojs-ui-core,oojs-ui-widgets,oojs-ui.styles.icons-interactions|hidden]|articlefeedback-core.js|articlefeedback.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.