Descending Slopes with RigidBody2d

Hello, I am making a platformer 2d with slopes and I am trying to make that my character could descend slopes.

I am following this tutorial:

But I have a problem, I am making this with RigidBody2d.

I tried to adapt this method with a RibigBody2d but I cannot make it work.

This is how I move my player:

Code (CSharp):

1. h = Input.GetAxisRaw("Horizontal");
2.  
3. transformada.position = transformada.position + new Vector3(velocidad * h * Time.deltaTime, 0, 0);

Here it is the code I tried to adapt:

Code (CSharp):

1. Debug.DrawRay(transform.position, new Vector2(0, -1.5f),Color.red);
2.         hit = Physics2D.Raycast(transform.position, new Vector2(0, -1.5f), 1.5f,layerRampa);
3.  
4.         if (hit)
5.         {
6.             float anguloRampa = Vector2.Angle(hit.normal,Vector2.up);
7.             if (anguloRampa>10)
8.             {
9.                 if (Mathf.Sign(hit.normal.x) == transform.localScale.x)
10.                 {
11.                     if (hit.distance-distancia <= Mathf.Tan(anguloRampa*Mathf.Deg2Rad) * Mathf.Abs(myBody.velocity.x))
12.                     {
13.                         float movimiento = Mathf.Abs(myBody.velocity.x);
14.                         float movimientoDescendenteY = Mathf.Sin(anguloRampa * Mathf.Deg2Rad) * movimiento;
15.                         myBody.velocity = new Vector2(Mathf.Cos(anguloRampa * Mathf.Deg2Rad) * movimiento * Mathf.Sign(myBody.velocity.x), myBody.velocity.y);
16.                         myBody.velocity = new Vector2(myBody.velocity.x, movimientoDescendenteY);
17.                     }
18.                 }
19.             }
20.         }

Thank you for your time