how do i make an object move the direction its facing?

i need this:

rigidbody2d.velocity = Vector2.up * hitPower;

turned into a way for it to move forward instead of up

here is all the code if needed:
public class Player : MonoBehaviour
{
[SerializeField] private LayerMask platformsLayerMask;
private Player_Base playerBase;
private Rigidbody2D rigidbody2d;
private CircleCollider2D circleCollider2d;

    private void Awake()
    {
        playerBase = gameObject.GetComponent<Player_Base>();
        rigidbody2d = transform.GetComponent<Rigidbody2D>();
        circleCollider2d = transform.GetComponent<CircleCollider2D>();
    }

    private void Update()
    {
        if (IsGrounded() && Input.GetKeyDown(KeyCode.Space))
        {
            float hitPower = 10f;
            rigidbody2d.velocity = Vector2.up * hitPower;
        }
    }

    private bool IsGrounded()
    {
        RaycastHit2D raycastHit2d = Physics2D.BoxCast(circleCollider2d.bounds.center, circleCollider2d.bounds.size, 0f, Vector2.down, .1f, platformsLayerMask);
        Debug.Log(raycastHit2d.collider);
        return raycastHit2d.collider != null;
    }
}

2d rigidbodies cant move forward, thats why is 2d, you would have to A, use a rigidbody 3d and Vector3.forward or rotate the 2d rigidbody so thaat up starts pointing forward