This is how application menu on my Mac.
And this is on ubuntu 18.04.
There is only a menu item quit
inside Pycharm on the top bar, other menu items like File, Edit, View are on the different bar, how can I make it look like macOS?
BTW, when I googling it, I found this extension. but looks like it doesn't work on 18.04 and makes system unstable.
I know for a fact that Unity has it. It's slightly hidden though. It only shows when you are hovering your mouse over title bar.
GNOME cannot do this.
Unity can and is still available in the 20.04 repositories. Or, you can try the free Ubuntu Unity remix -- https://ubuntuunity.org/
I am running this on 1 machine and it's pretty good. Not perfect but it works.
Alternatively, I believe that both MATE and KDE 5 can be customised to look and work in a Mac-like manner, with a global menu bar at the top of the screen and a dock for launching and switching apps along one screen edge. I have not tried this myself, though.
KDE: https://www.dedoimedo.com/computers/plasma-look-like-mac.html
MATE: http://mate-macos.blogspot.com/p/making-ubuntu-mate-look-like-macos.html
Of course both MATE and KDE have Ubuntu flavours.