$ sudo apt-get update
$ sudo apt-get install initramfs-tools-bin 

initramfs-tools-bin is installed in your system.

Make ensure the initramfs-tools-bin package were installed using the commands given below,

$ sudo dpkg-query -l | grep initramfs-tools-bin *

You will get with initramfs-tools-bin package name, version, architecture and description in a table

initramfs-tools-bin package basic information: