Install PHP 7.4 on Apache Ubuntu 18.04
Add PPA for PHP 7.4
Add the ondrej/php which has PHP 7.4 package and other required PHP extensions.
sudo apt install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt update
Once you have added the PPA you can install PHP 7.4.
sudo apt install php7.4
Verify PHP 7.4 is installed
php -v
Install PHP 7.4 Extensions
Installing PHP extensions are simple with the following syntax.
sudo apt install php7.4-**extension_name**
Some common php extensions install command
sudo apt install php7.4-common php7.4-mysql php7.4-xml php7.4-xmlrpc php7.4-curl php7.4-gd php7.4-imagick php7.4-cli php7.4-dev php7.4-imap php7.4-mbstring php7.4-opcache php7.4-soap php7.4-zip php7.4-intl -y
Configure PHP 7.4 Apache
sudo nano /etc/php/7.4/apache2/php.ini