Usermod pam in hpux

On pam.conf

usermod auth required libpam_hpsec.so.1
usermod auth sufficient libpam_krb5.so.1
usermod auth required libpam_unix.so.1 try_first_pass
usermod account required libpam_hpsec.so.1
usermod account sufficient libpam_krb5.so.1
usermod account required libpam_unix.so.1
usermod session required libpam_hpsec.so.1
usermod session sufficient libpam_krb5.so.1
usermod session required libpam_unix.so.1

but when i try

[root@hpux etc]# usermod -G wheel giuseppe
Login 'giuseppe' does not exist
[root@hpux etc]# id giuseppe
uid=10012(giuseppe) gid=10000(domain users)

Giuseppe is ad user
How to set usermod?
thanks

---------- Post updated at 02:24 PM ---------- Previous update was at 01:30 PM ----------

works fine after reboot