Answers for "update php version to php 7.4"

update php version ubuntu 7.3

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install -y php7.3

update to php 7.4

Add the ondrej/php PPA. Ubuntu: ...
Install PHP 7.4 and required extensions. To install PHP 7.4 core. ...
PHP 7.4 for web: ...
Uninstall old PHP versions: ...
Verify PHP 7.4 installation