Guys, Opera team is very busy working on more serious issues related to sidebar:
https://blogs.opera.com/desktop/changelog-for-62/
DNA-78081 [Mac][Lin] Sidebar menu button doesn’t work
DNA-78090 [Mac] Browser crashes when logging out from Telegram sidebar app
DNA-76911 Sidebar messengers error pages doesn’t recognize dark mode
DNA-77467 [Mac] The extensions sidebar is white in dark theme
DNA-77571 Highlighted O-menu inverse colour when sidebar is hidden