To unlock apex workspace users account

SQL> SELECT workspace_id FROM apex_workspaces WHERE workspace = 'Worksapce_name';
          WORKSPACE_ID
          10567
Find  the APEX schema’s name for your version:
SQL> select username from dba_users where username like 'APEX%' order by 1;
    USERNAME
    APEX
    APEX_050200
    APEX_PUBLIC_USER


SQL> alter session set current_schema = APEX_050200;                    
Session altered.
SQL>


Unlock your ADMIN account with the following code:
 SQL> begin
      wwv_flow_security.g_security_group_id := 10567;
      wwv_flow_fnd_user_api.UNLOCK_ACCOUNT('username');
      commit;
    end;
    /
PL/SQL procedure successfully completed.
SQL>