ubuntu 20.04 php how to set php version 8.0.3 to 7.3 code example

Example 1: install php 7.4 on ubuntu 20.04

sudo apt update
sudo apt install php7.4
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

Example 2: how to change php version 8 to 7.1 in ubuntu 20.04

$ sudo apt install python-software-properties
$ sudo add-apt-repository ppa:ondrej/php