$ sudo apt-get update
$ sudo apt-get install libpgf6 

libpgf6 is installed in your system.

Make ensure the libpgf6 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libpgf6 *

You will get with libpgf6 package name, version, architecture and description in a table

libpgf6 package basic information: