authen::krb5::admin : create principal

[FM]

Hello,
Do you have example to manage kerberos db using perl
I create a simple test script :

$handle = 
Authen::Krb5::Admin->init_with_password("$ADMINPRINC","$adminpass");
$kp=Authen::krb5::get_default_realm();
print $kp;

but I received :
Undefined subroutine &Authen::krb5::get_default_realm

I'd like to be able to add principal and change password for existing 
users (2 scripts are fine).