running php 5.6 and 7 ubuntu code example

Example 1: install php 7.3 ubuntu

sudo apt install php7.3-cli php7.3-fpm php7.3-json php7.3-pdo php7.3-mysql php7.3-zip php7.3-gd  php7.3-mbstring php7.3-curl php7.3-xml php7.3-bcmath php7.3-json

Example 2: install php 5.6 on ubuntu 18.04

$ sudo add-apt-repository ppa:ondrej/php