Where's the Help menu link to "Documentation"? That's a basic requirement in the Help menu.
During April we've had a small glitch in the system and some of the links were not displayed. The issue has been corrected since and you should now be able to see the help link.
You can access Product Documentation by clicking on "Adobe Experience Cloud Learn & Support" which is listed above "Learning" and "Community" in Experience Cloud when you are not yet in a specific solution:
From there, click on "Experience League" (the center option):
Now you are in Experience League - select "Learn" at the top, and then click on "Documentation" in the drop-down menu:
(*You can access the same Experience League dropdown menu above that links to Documentation if you were to have initially selected "Learning" instead of "Adobe Experience Cloud Learn & Support" because that button links directly to Experience League)
I hope this is helpful!