fawiki is among the pilot wikis on which latest Desktop Improvements are being implemented. The new language selector (which displays in the page header) got recently deployed. It works fine when there are language links. But, when a page is still not connected to a Wikidata entry, it used to be possible to add a language link in the old view with a few clicks and without leaving fawiki but now it is not possible.
This is how the legacy Vector looked like, and I have marked in red the link that would allow you to add a lang link without leaving fawiki:
{F34532010}
This feature is now missing; essentially, the latest Desktop Improvement has introduced a regression.
PS: if it helps, the code behind that screenshot is [[https://gerrit.wikimedia.org/g/mediawiki/extensions/Wikibase/+/3b08c2b2ffce409fd103e2c0b7fc053b7f07bb21/client/includes/RepoItemLinkGenerator.php#159|this]] and there is a JS script that overrides the `click` event for the link with `class=wbc-editpage` but I don't know where that JS actually lives.