$ sudo apt-get update
$ sudo apt-get install libghc-websockets-prof 

libghc-websockets-prof is installed in your system.

Make ensure the libghc-websockets-prof package were installed using the commands given below,

$ sudo dpkg-query -l | grep libghc-websockets-prof *

You will get with libghc-websockets-prof package name, version, architecture and description in a table

libghc-websockets-prof package basic information: