Special
Gadgets/export/Sandbox
From Dogcraft Wiki
To export the Sandbox gadget, click on "Download" button, save the downloaded file, go to Special:Import on destination wiki and upload it. Then add the following to MediaWiki:Gadgets-definition page:
* Sandbox[ResourceLoader|rights = block|dependencies=mediawiki.util]|sandbox.js|sandbox.css
You must have appropriate permissions on destination wiki (including the right to edit system messages) and import from file uploads must be enabled.