sudo 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 distro

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 -y

# Update the package index
sudo apt update
# Install PHP 7.4 and necessary extensions
sudo apt install php7.4
# Verify the installation
php -v