I've added an additional PHP version as per the document on the site.
If I recheck setting: The following PHP versions are available : 7.0.33 (/usr/bin/php-cgi7.0), 7.3.3 (/usr/bin/php-cgi7.3), 7.0 (mod_php) No PHP-FPM packages were found on this system.
Run CGI scripts as domain owner? Yes
PHP script execution mode FCGId (run as virtual server owner)
It is using: /etc/php/7.3/apache2/php.ini rather than the one in the virtual host Also the process running is www-data