LDAP Extension .so

Hi,

When I try to run Ldap on my Linuxserver I'll get the error : Fatal error: Call to undefined function ldap_connect() in /var/www/modules/ldap_integration/ldap_integration/LDAPInterface.php on line 132.

When I look on the internet they say that I should comment out: extension=php_ldap.so or .dll but I can't find neither in my php.ini.

Is their a way that I haven't installed LDAP on my server in some kind of way?

Thanks in advance!