Install x3270-doc by entering the following commands in the terminal:
sudo apt update sudo apt install x3270-doc
Description:
X11 program for telnet sessions to IBM mainframes - documentation
x3270-doc contains the HTML documentation for the x3270 series of programs that allows one to connect to IBM mainframes via telnet.
Homepage: http://x3270.bgp.nu/
Version: 3.6ga4-3
Section: universe/doc