Insert data into tables with REF

!Good!

I am doing an exercise on Relational Objects in Database. The truth is that I am a bit lost, and I need to insert some data in a table that I have created in the following way:

CREATE TABLE empleados OF Empleado(
idEmpleado PRIMARY KEY);

And the object type is this:

CREATE OR REPLACE TYPE Empleado AS OBJECT(
idEmpleado NUMBER,
nombre VARCHAR(20),
apellidos VARCHAR(20),
salario NUMBER,
vencargado REF Encargado,
MAP MEMBER FUNCTION ordenarID return NUMBER,
MEMBER FUNCTION encargadoEmpleado return Encargado);
CREATE OR REPLACE TYPE BODY Empleado
AS
MAP MEMBER FUNCTION ordenarID return NUMBER
IS
BEGIN
RETURN idEmpleado;
END;
END;

Where the attribute of vencargadocomes from this other object type:

CREATE TYPE Encargado AS OBJECT(
idEncargado NUMBER,
nombre VARCHAR(20),
apellidos VARCHAR(20),
cargo VARCHAR(20),
MAP MEMBER FUNCTION ordenarID return NUMBER,
MEMBER FUNCTION empleadosCargo return NUMBER);
CREATE TYPE BODY Encargado
AS
MAP MEMBER FUNCTION ordenarID return NUMBER
IS
BEGIN
RETURN idEncargado;
END;
END;

I have tried to add some data to the employees table and this error has occurred to me, and I don't know how to enter the values:

inconsistent data types: expected REF got NUMBER

I have added them like this:

INSERT INTO empleados VALUES ( Empleado(1,'Juan','Rodriguez',1600,1));

If someone can guide me, it would be very helpful. Thanks.