$ sudo apt-get update
$ sudo apt-get install freeradius-dialupadmin 

freeradius-dialupadmin is installed in your system.

Make ensure the freeradius-dialupadmin package were installed using the commands given below,

$ sudo dpkg-query -l | grep freeradius-dialupadmin *

You will get with freeradius-dialupadmin package name, version, architecture and description in a table

freeradius-dialupadmin package basic information: