For install all important php 7.4 extensions
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 -ysudo apt install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt update
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
// Last part is stolen from Lokesh003Coding's answer <3
// This snippet should work on the currently most recent Linux distrosudo apt update
sudo apt install php php-cli php-fpm php-json php-pdo php-mysql php-zip php-gd php-mbstring php-curl php-xml php-pear php-bcmath