To Change PHP VERSION in ubuntu Run below command then select php version sudo update-alternatives --config php sudo update-alternatives --config php select a version//In ubunutu Default PHP 7.1 is set on your system and you need to switch to PHP 5.6 $ sudo a2dismod php7.1 $ sudo a2enmod php5.6 $ sudo service apache2 restart sudo update-alternatives --set php /usr/bin/php5.6$ sudo update-alternatives --config php or $ sudo a2enmod php7.1(version) Interactive switching mode sudo update-alternatives --config php sudo update-alternatives --config phar sudo update-alternatives --config phar.phar Manual Switching From PHP 5.6 => PHP 7.1 Default PHP 5.6 is set on your system and you need to switch to PHP 7.1. Apache: $ sudo a2dismod php5.6 $ sudo a2enmod php7.1 $ sudo service apache2 restart Command Line: $ sudo update-alternatives --set php /usr/bin/php7.1 $ sudo update-alternatives --set phar /usr/bin/phar7.1 $ sudo update-alternatives --set phar.phar /usr/bin/phar.phar7.1 From PHP 7.1 => PHP 5.6 Default PHP 7.1 is set on your system and you need to switch to PHP 5.6. Apache: $ sudo a2dismod php7.1 $ sudo a2enmod php5.6 $ sudo service apache2 restart Command Line: $ sudo update-alternatives --set php /usr/bin/php5.6 # Change to PHP 7.4: sudo update-alternatives --set php /usr/bin/php7.4 # Change to PHP 8.0: sudo update-alternatives --set php /usr/bin/php8.0 # Change to PHP 8.1: sudo update-alternatives --set php /usr/bin/php8.1sudo a2dismod php7.1 sudo a2enmod php5.6 sudo service apache2 restart #command Line sudo update-alternatives --set php /usr/bin/php5.6 $ sudo update-alternatives --set php /usr/bin/php7.1 $ sudo update-alternatives --set phar /usr/bin/phar7.1 $ sudo update-alternatives --set phar.phar /usr/bin/phar.phar7.1PATH="/usr/local/php74/bin/:${path}"sudo update-alternatives --config php sudo update-alternatives --config phar sudo update-alternatives --config phar.pharsudo update-alternatives --config php sudo update-alternatives --set php /usr/bin/php5.6