Gadget export
To export the Twinkle-beta 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:
* Twinkle-beta[ResourceLoader|dependencies=ext.gadget.morebits-beta,ext.gadget.select2,mediawiki.api,mediawiki.language|rights=autoconfirmed,import|type=general|peers=Twinkle-pagestyles-beta]|Twinkle-beta.js|Twinkle-beta.css|twinklearv-beta.js|twinklewarn-beta.js|twinkleblock-beta.js|friendlywelcome-beta.js|friendlyshared-beta.js|friendlytalkback-beta.js|twinklespeedy-beta.js|twinkleprod-beta.js|twinklexfd-beta.js|twinkleimage-beta.js|twinkleprotect-beta.js|friendlytag-beta.js|twinklediff-beta.js|twinkleunlink-beta.js|twinklefluff-beta.js|twinkledeprod-beta.js|twinklebatchdelete-beta.js|twinklebatchprotect-beta.js|twinklebatchundelete-beta.js|twinkleconfig-beta.js
You must have appropriate permissions on the destination wiki (including the right to edit system messages) and import from file uploads must be enabled.