J4.x:Error fetching help page in the administrator console
From Joomla! Documentation
When I select the Help on any screen of the administrator console, a popup opens with a 404 error: 'Error fetching page from MediaWiki API: The page you specified doesn't exist.'
This pertains only to Joomla! version(s): 4.3.0
What is the cause
There is missing proxy information that will be resolved soon.
How to fix
A fix has been released and the issue no longer exists.
Review the Release 4.3 Help Screens directly