$ sudo apt-get update
$ sudo apt-get install libunicode-string-perl 

libunicode-string-perl is installed in your system.

Make ensure the libunicode-string-perl package were installed using the commands given below,

$ sudo dpkg-query -l | grep libunicode-string-perl *

You will get with libunicode-string-perl package name, version, architecture and description in a table

libunicode-string-perl package basic information: