Unity 2D Movement doesnt work

Question

using UnityEngine;

public class Movement3 : MonoBehaviour
{

    public Rigidbody2D rb;

    public float forwardForce = 2000f;

    // Update is called once per frame
    void FixedUpdate()
    {
        if (Input.GetKey("a"))
        {
            rb.AddForce(10, 0);
        }

        if (Input.GetKey("d"))
        {
            rb.AddForce(-10, 0);
        }

        if (Input.GetKey("space"))
        {
            rb.AddForce(0, 50);
        }

    }
}

I worked out this code but it doesnt work and i dont know why