DBMS_RLS.add_policy: object_name not working

Question

• Hi guys, I'm learning the VPD feature of Oracle and I've got stuck at these below codes.

BEGIN
    DBMS_RLS.add_policy(
    object_schema    => 'user_bacsi_01',
    object_name      => 'HOSOBENHNHAN',
    policy_name      => 'VPD_POLICY_DOCTOR_SEE_PATIENT_INFO',
    policy_function  => 'FUNC_VPD_POLICY_DOCTOR_SEE_PATIENT_INFO'
    );
END;
/

• Error

Error report -
ORA-00942: table or view does not exist
ORA-06512: at "SYS.DBMS_RLS_INT", line 23
ORA-06512: at "SYS.DBMS_RLS", line 54
ORA-06512: at line 2
00942. 00000 -  "table or view does not exist"
*Cause:    
*Action:

• I've already created the table name 'HOSOBENHNHAN'. I don't understand the problem. Please help me!
• Thank you!