Binary package “perl-tk” in ubuntu focal

Perl module providing the Tk graphics library

 Perl/Tk (also known as pTk or ptk) is a collection of modules and
 code that attempts to wed the easily configured Tk widget toolkit
 to the powerful lexigraphic, dynamic memory, I/O, and object-oriented
 capabilities of Perl 5. In other words, it is an interpreted
 scripting language for making widgets and programs with Graphical
 User Interfaces (GUI).
 .
 A good place to get started is by running the "widget" demo that's
 installed with this package.