How to install libpng12-0 in Ubuntu 18.04

Add a line into your /etc/apt/sources.list:

deb http://security.ubuntu.com/ubuntu xenial-security main

then

sudo apt-get update -y
sudo apt-get install -y libpng12-0

OK.

Referrence:

https://packages.ubuntu.com/xenial/amd64/libpng12-0/download