$ sudo apt-get update
$ sudo apt-get install myspell-tl 

myspell-tl is installed in your system.

Make ensure the myspell-tl package were installed using the commands given below,

$ sudo dpkg-query -l | grep myspell-tl *

You will get with myspell-tl package name, version, architecture and description in a table

myspell-tl package basic information: