It is pretty unlikely that you want to use PAM if you are using kubernetes and running in containers. PAM is generally for logging into a machine where you already have usernames and passwords set up for other purposes.
If you are talking about creating accounts, it is likely that you want to use a different authenticator (external OAuth providers are what I usually recommend since there are no user credentials to manage), but you can also use e.g. native-authenticator to set up usernames and passwords in a more jupyterhub-native way.