请注意：PHP7.4已经于2022年11月28日停止维护。

安装sury源：

#!/bin/sh
# To add this repository please do:
if [ "$(whoami)" != "root" ]; then
    SUDO=sudo
fi
${SUDO} apt-get update
${SUDO} apt-get -y install lsb-release ca-certificates curl
${SUDO} curl -sSLo /tmp/debsuryorg-archive-keyring.deb https://packages.sury.org/debsuryorg-archive-keyring.deb
${SUDO} dpkg -i /tmp/debsuryorg-archive-keyring.deb
${SUDO} sh -c 'echo "deb [signed-by=/usr/share/keyrings/deb.sury.org-php.gpg] https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list'
${SUDO} apt-get update

安装PHP7.4：

apt install -y php7.4-fpm php7.4-mysql php7.4-mbstring php7.4-curl php7.4-xml php7.4-imagick php7.4-zip php7.4-gd php7.4-intl php7.4-bcmath