create a script for moving a 2d character in unity

void Update()
{
    if (Input.GetKeyUp(KeyCode.A))
    {
        rb.AddForce(new Vector2(-1, 0), ForceMode2D.Impulse);
    }
    if (Input.GetKeyUp(KeyCode.D))
    {
        rb.AddForce(new Vector2(1, 0), ForceMode2D.Impulse);
    }
    if (Input.GetKeyUp(KeyCode.W))
    {
        rb.AddForce(new Vector2(0, 1), ForceMode2D.Impulse);
    }
    if (Input.GetKeyUp(KeyCode.S))
    {
        rb.AddForce(new Vector2(0, -1), ForceMode2D.Impulse);
    }
}