Please tell me if you’re talking about the desktop or phone version, also if you’ve installed Style Settings, otherwise you won’t be able to access Obsidians and Dune’s preferences.
Tonight I’ll change the visibility behavior of the left ribbon from hidden to visible - I understand that new users may be confused if they can’t see anymore their preferences. Sorry and thanks for letting me know.
Meanwhile you can open the preferences if you go to
A. Obsidians top menu bar, generated by your system Obsidian>preferences or
B. Another way is to invoke your command palette and type: open settings