$ sudo apt-get update
$ sudo apt-get install libfreeradius-dev 

libfreeradius-dev is installed in your system.

Make ensure the libfreeradius-dev package were installed using the commands given below,

$ sudo dpkg-query -l | grep libfreeradius-dev *

You will get with libfreeradius-dev package name, version, architecture and description in a table

libfreeradius-dev package basic information: