$ sudo apt-get update
$ sudo apt-get install ko.tex-extra-hlfont 

ko.tex-extra-hlfont is installed in your system.

Make ensure the ko.tex-extra-hlfont package were installed using the commands given below,

$ sudo dpkg-query -l | grep ko.tex-extra-hlfont *

You will get with ko.tex-extra-hlfont package name, version, architecture and description in a table

ko.tex-extra-hlfont package basic information: