$ sudo apt-get update
$ sudo apt-get install libdecodeqr-examples 

libdecodeqr-examples is installed in your system.

Make ensure the libdecodeqr-examples package were installed using the commands given below,

$ sudo dpkg-query -l | grep libdecodeqr-examples *

You will get with libdecodeqr-examples package name, version, architecture and description in a table

libdecodeqr-examples package basic information: