Hello Friends, Now let's see This tutorial shows you update php 7.2 to 7.3 ubuntu. it's simple example of upgrade php 7.2 to 7.3 ubuntu. step by step explain how to upgrade php 7.2 to 7.3 ubuntu. i explained simply about ubuntu update php 7.2 to 7.3. You just need to some step to done ubuntu 20 upgrade php 7.2 to 7.3.

just follow bellow command to update php 7.2 to php 7.3 in ubuntu os.

        sudo add-apt-repository ppa:ondrej/php
        sudo apt-get update
          
        sudo apt install php7.3

        sudo apt install php7.3-common php7.3-cli php7.3-bcmath php7.3-bz2 php7.3-curl php7.3-gd php7.3-intl php7.3-json php7.3-mbstring php7.3-readline php7.3-xml php7.3-zip php7.3-fpm

        sudo a2dismod php7.2
        sudo a2enmod php7.3
          
        sudo service apache2 restart

now you can check php version:

It will help you..