Go to https://wikitech.wikimedia.org/wiki/Special:CreateAccount and fill out all fields.
Get an error ⧼authmanager-authplugin-create-fail⧽ (literally).
This was reported in https://www.mediawiki.org/wiki/Topic:Wngszzt4a01micef by @MarcoFalda, coming from T252788.
I can confirm this problem. This problem blocks code contributions.