I am unable to update php 5.5.9 to 7.2 on ubuntu 14.04 getting error as unable to locate package. URGENT

Hi Community Members,

I am having some issues in updating the PHP version from 5.59 to 7 or 7.1 or 7.2. I tried below commands

sudo add-apt-repository ppa:ondrej/php sudo apt-get update sudo apt-get install php7.2

but i am getting error as

unable to locate package php7.2 couldn’t find any package by regex ‘php7.2’

Also followed but having same error

https://www.digitalocean.com/community/tutorials/how-to-upgrade-to-php-7-on-ubuntu-14-04

How To Upgrade to PHP 7 on Ubuntu 14.04 (Answers provided frequently asked questions)

Any help/suggestion/guidance will be appreciated.