Tecadmin published a tutorial about installing PHP 7.4, 7.3, 7.2 and 5.6 via PPA on Ubuntu 20.04 LTS.
How to Install PHP on Ubuntu 20.04
PHP 7.4 is the latest stable release available. Say thanks to Ondřej Surý for maintaining PPA of most the popular PHP versions on launchpad. If you want to install a specific or multiple version of PHP, then this article can be helpful for you. This article will help you to install PHP 7.4, 7.3, 7.2 and 5.6 on Ubuntu 20.04 (Focal Fossa) via PPA.
How to Install PHP on Ubuntu 20.04
