i installed gnome-online-accounts. but it doesn't appear anywhere in the system. how can i start it
$ sudo apt install gnome-control-center
$ gnome-control-center online account
(gnome-control-center:28414): Gtk-ERROR **: 15:51:15.425: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported
what goes wrong ?