$ sudo apt-get update
$ sudo apt-get install libssh-dbg 

libssh-dbg is installed in your system.

Make ensure the libssh-dbg package were installed using the commands given below,

$ sudo dpkg-query -l | grep libssh-dbg *

You will get with libssh-dbg package name, version, architecture and description in a table

libssh-dbg package basic information: