$ sudo apt-get update
$ sudo apt-get install libqcustomplot1.1-dbg 

libqcustomplot1.1-dbg is installed in your system.

Make ensure the libqcustomplot1.1-dbg package were installed using the commands given below,

$ sudo dpkg-query -l | grep libqcustomplot1.1-dbg *

You will get with libqcustomplot1.1-dbg package name, version, architecture and description in a table

libqcustomplot1.1-dbg package basic information: