$ sudo apt-get update
$ sudo apt-get install liballegro-dialog5.2 

liballegro-dialog5.2 is installed in your system.

Make ensure the liballegro-dialog5.2 package were installed using the commands given below,

$ sudo dpkg-query -l | grep liballegro-dialog5.2 *

You will get with liballegro-dialog5.2 package name, version, architecture and description in a table

liballegro-dialog5.2 package basic information: