Package php5 have no installation candidate (Ubuntu 16.04)

It looks like the package php5 is no longer available in the repositories for Ubuntu 16.04.

Instead, you can try installing the latest version of PHP by running the following command:

sudo apt-get install php

This will install the latest version of PHP, which is currently PHP 7.4.

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If you need to install a specific version of PHP, you can add the PPA (Personal Package Archive) for the version you want to use. For example, to install PHP 7.3, you can run the following commands:

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
sudo apt-get install php7.3