[Samba] Users shell

[M Azer]

since i am using "template shell = /bin/bash" in my smb.conf all of our
users have access to the shell. how do i prevent certain users from being
able to login using the shell

 getent passwd cat
cat:*:10016:10002:cat:/home/CAD/cat:/bin/bash
how do i change the user "cat" shell to /sbin/nologin

I know if the user was a local user /etc/passwd i could use "usermode -s
/sbin/nologin cat