Install gir1.2-gladeui-2.0 by entering the following commands in the terminal:
sudo apt update sudo apt install gir1.2-gladeui-2.0
Description:
GObject introspection data for the GTK+ User Interface library
Glade is a RAD tool to enable quick and easy development of user interfaces for the GTK+ toolkit. . Glade is, since its "3.0" major version, highly modular, and composed of widgets which can be used by other applications to integrate functionality similar to the one provided by the Glade application itself. . This package contains introspection data for the GTK+ User Interface Build core library.
Homepage: https://glade.gnome.org/
Version: 3.22.1-1
Section: universe/introspection