ORA-28000: the account is locked

Cause: The user has entered wrong password consequently for maximum number
of times specified by the user"s profile parameter FAILED_LOGIN_ATTEMPTS, or
the DBA has locked the account

Solution:- Contact oracle dba or unlock the user account using below queries.

sql>alter user username unlock;
if the user is locked by user has entered maximum number of times wrong password then use the below query to unlock the account.
simple method.
sql>alter user username account unlock;
one more method.
sql>alter user username identified by new_password account unlock;