Problem with Rigidbody2D.Addforce

Hi, i’m a total Noob so i would like an explanation and maybe a simple script written by you (?).

So… what’s wrong with this script? It doesnt do anything.

#pragma strict

function FixedUpdate () {

if (Input.GetKeyDown(KeyCode.A))
    rigidbody2D.AddForce(Vector2.up * 10);
   

}

check if you attacched a rigidbody2D not a rigidbody (3d)