How to log user commands into server accounting file?

[shahriarbasiri]

I was working with a NOS which uses pam_tacplus for tacacs and I found that it logs user commands to server ( /var/log/tac_plus.acct) but when I config ssh pam files the same as the NOS on other devices, it doesn't log any user commands to server.
Firstly, I was thinking that if I config the session part in pam to use tacplus.so then I'll have the accounting, but apparently that is not the case. I also checked the pam_sm_open_session and I found that no "cmd" input is passed to _pam_account().
So, my next question is how a user application should send log of user commands to server? Apparently there is no standard API for that and the user should manually call the _pam_account() ?