I would like to add the "workspaces switcher" in GNOME classic's taskbar of my ubuntu 20.04. The right-click of the mouse has no response.
I've installed the gnome-tweak-tool, and the "mouse & touchpad" page in it has nothing to do with that. Could anyone please help me?
IMHO it is time to switch to Ubuntu MATE. Here you can do more. See this answer for details. About customization see guide.
Workspace switcher on MATE allows at least window move between workspaces by mouse:
To start using Ubuntu MATE on top of existing desktop you need to install it by
sudo apt-get install ubuntu-mate-desktop^
then reboot and select MATE session on login screen.
