How to set password complexity in Linux?

Question

linux

Tell me where I'm doing wrong?
installed the following:

PASS_MAX_DAYS   2
PASS_MIN_DAYS   1
PASS_MIN_LEN    8
PASS_WARN_AGE   1

password    requisite     pam_cracklib.so try_first_pass retry=3 type= ucredit=-2 lcredit=-2 dcredit=-2 ocredit=-2
password    sufficient    pam_unix.so sha512 shadow nullok try_first_pass use_authtok remember=5

but in cat /etc/shadow it shows something else:
:16596:0:99999:7:::
Addition: created a new user and changed to this one:
:16596:1:2:1:::
apparently it only works for new users?