$ im-settings select ibus
or
$ mkdir ~/.config/input-method
$ cd ~/.config/input-method
$ ln -s /usr/lib/input-method/profile.d/ibus target
This settings are used for all the users who does not have user-level preference above.
$ mkdir /etc/xdg/input-method
$ cd /etc/xdg/input-method
$ ln -s /usr/lib/input-method/profile.d/ibus target
$ im-settings config --set global.ooo_force_desktop_gnome ture
If the current desktop environment is KDE and an Kimpanel applet is placed on the desktop, the launch script included in this launcher enables IBus Kimpanel panel application. Otherwise, the script selects ibus-ui-gtk3.
If you want to force ibus-ui-gtk3, run the follwoing command:
$ im-settings config --set ibus.panel=/usr/lib64/ibus/ibus-ui-gtk3
Note that the path to ibus-ui-gtk3 might be different in your environment.