fcitx5-frontend-gtk3 binary package in Ubuntu Lunar s390x

 Fcitx5 is the next generation of fcitx input method framework. It
 provides pleasant and modern input experience with intuitive graphical
 configuration tools. The framework is highly extensible with support
 for GTK+ and Qt toolkits, DBus interfaces, a large variety of desktop
 environments and a developer-friendly API.
 .
 Some of its new features include support of both Wayland and Xorg
 and the ability to mimic IBus Input Method Framework in order to
 provide better compatibility across different Linux distributions
 and desktop environments.
 .
 This package provides the im module of fcitx5. Users of GTK3-based
 applications are highly recommended to have this package installed
 for better input method support.

Source package