Install fcitx-frontend-gtk3 by entering the following commands in the terminal:
sudo apt update sudo apt install fcitx-frontend-gtk3
Description:
Flexible Input Method Framework - GTK+ 3 IM Module frontend
Fcitx is a input method framework with extension support, which provides an interface for entering characters of different scripts in applications using a variety of mapping systems. . It offers a pleasant and modern experience, with intuitive graphical configuration tools and customizable skins and mapping tables. It is highly modularized and extensible, with GTK+ 2/3 and Qt4 IM Modules, support for UIs based on Fbterm, pure Xlib, GTK+, or KDE, and a developer-friendly API. . This package provides the GTK+ 3 IM Module frontend, which is recommended for all desktop users. This is the best solution if you are looking for a better input experience with GTK+ 3 applications.
Homepage: https://github.com/fcitx/fcitx
Version: 1:4.2.9.6-1
Section: universe/utils