This shows my version details

Trying to set up a cron job for the fetching of email.
Just running the php file manually to see if it works properly I get the following error:
/var/www/html/ticket/api# php cron.php
PHP Fatal error: Uncaught Error: Call to undefined function mysqli_init() in /var/www/html/ticket/include/mysqli.php:28
Stack trace:
#0 /var/www/html/ticket/bootstrap.php(205): db_connect()
#1 /var/www/html/ticket/main.inc.php(28): Bootstrap::connect()
#2 /var/www/html/ticket/api/api.inc.php(32): require_once('...')
#3 /var/www/html/ticket/api/cron.php(17): require('...')
#4 {main}
thrown in /var/www/html/ticket/include/mysqli.php on line 28
Does anyone know what might be wrong?