The password expiration notice is actually an Oracle error, ORA-28002: the password will expire within days. To avoid the error, we have to make the lifetime of password span longer or unlimited.
First of all, make sure that you're in the right database.
SQL> select name from v$database;
NAME
---------------------------
ORCL
Check what profile the user is applied.
SQL> select profile from dba_users where username = 'STEVE';
PROFILE
--------------------------------------------------------------------------------
DEFAULT
We set unlimited PASSWORD_LIFE_TIME on profile DEFAULT.
SQL> alter profile default limit password_life_time unlimited;
Profile altered.