Canon Ball shooting with Instiate

Hello ,

Well I created a mini games when I direct my Canon ball and when I click on the Space key , Red Ball must be projected to the direction of my Canon ! everything works (time down , rotating the barrel, instantiation of prefab .. ) but the problem is that when I click on space, my cannon projectile force does not apply , I just set it on 1800F as a Force! well here's my images and scripts that I use :

I put a script on the Canon to control the rotation, and a script on the gameobject or I add my prefab of the red ball :

Here is the script of my CanonController :

 using UnityEngine;
 using System.Collections;
  
 public class CanonController : MonoBehaviour {
  
  
     private float horizontal;
     public float maxAngle = -30;
     public float minAngle = -145;
  
     public float rotateSpeed = 1f;
  
     float currentAngle = -90;
     Vector3 initialAngle;
     Quaternion rotationTarget;
  
     // Use this for initialization
     void Start () {
  
         initialAngle = transform.eulerAngles;
  
     }
      
     // Update is called once per frame
     void Update () {
  
  
         horizontal = Input.GetAxisRaw("Horizontal");
  
         if (horizontal > 0)
         {
             if(currentAngle < maxAngle)
             {
                 currentAngle += rotateSpeed;
             }
         }
  
  
         if (horizontal < 0)
         {
             if (currentAngle > minAngle)
             {
                 currentAngle -= rotateSpeed;
             }
         }
  
         rotationTarget = Quaternion.AngleAxis(currentAngle, Vector3.back);
  
         transform.localRotation = rotationTarget;
  
     }
 }

And the script of my prefab :

 using UnityEngine;
 using System.Collections;
  
 public class shootingGun : MonoBehaviour {
  
     public GameObject gunPrefab;
  
     GameObject gunPrefabClone;
  
     public float forForce = 300.0f;
  
     private float CurrentTime = 0;
  
     public float TimeToShoot = 1.5f;
  
     // Use this for initialization
     void Start () {
  
     }
      
     // Update is called once per frame
     void Update () {
  
         CurrentTime += Time.deltaTime;
         
     }
  
     void FixedUpdate()
     {
  
         if (Input.GetButtonDown("Jump") && CurrentTime >= TimeToShoot)
         {
  
             ShootBallMethod();
  
             CurrentTime = 0;
  
         }
     }
  
  
     void ShootBallMethod()
     {
  
         gunPrefabClone = Instantiate(gunPrefab, transform.position, Quaternion.identity) as GameObject;
  
         Rigidbody2D rb2dForClone = gunPrefabClone.GetComponent<Rigidbody2D>();
  
         rb2dForClone.AddForce(transform.forward * forForce,ForceMode2D.Force);
  
         Destroy(gunPrefabClone, 1.5f);
  
  
     }
 }

I wish to have the same result as this tutorial :

https://youtu.be/Mwr3oh7wlRc?t=10m58s

Thank you !