Hey can someone please help me with my ammobar

im trying to create an ammobar to keep track of my ammo and i set the value of the bar to my guns ammo but the problem is is that my gun is instantiated after the game starts and if i put the gun prefab as the gun it wont work please help if you know a solution.

public class AmmoBar : MonoBehaviour { public Slider ammoBar; Gun gunAmmo; public Gun gunn;

 private void Start()
 {
     gunAmmo = GetComponent<Gun>();
 }
     

 public void Update()
 {
     ammoBar.value = gunn.ammo;

} }

public class GunController : MonoBehaviour { public Transform weaponHold; public Gun startingGun; Gun equippedGun; AmmoBar ammoBar; void Start() { if (startingGun != null) { EquipGun(startingGun); } ammoBar = GetComponent(); equippedGun = ammoBar. }

 public void EquipGun(Gun gunToEquip)
 {
     if (equippedGun != null)
     {
         Destroy(equippedGun.gameObject);
     }
     equippedGun = Instantiate(gunToEquip, weaponHold.position, weaponHold.rotation) as Gun;
     equippedGun.transform.parent = weaponHold;
 }


 
 public void Shoot()
 {
     if (equippedGun != null)
     {
         equippedGun.Shoot();
         
     }
 }

}

public class Gun : MonoBehaviour {

 public int ammo;
 public Transform muzzle;
 public Projectile projectile;
 public float msBetweenShots = 100;
 public float muzzleVelocity = 35;
 GunController gun;
 float nextShotTime;

 public void Start()
 {
     ammo = 20;
 }

 

 public void Shoot()
 {

     {
         if (Time.time > nextShotTime)
         {
             if (ammo >= 1)
             {
                 ammo--;

                 nextShotTime = Time.time + msBetweenShots / 1000;
                 Projectile newProjectile = Instantiate(projectile, muzzle.position, muzzle.rotation) as Projectile;
                 newProjectile.SetSpeed(muzzleVelocity);


             }
         }
     }
 }

}

,public class AmmoBar : MonoBehaviour { public Slider ammoBar; Gun gunAmmo; public Gun gunn;

 private void Start()
 {
     gunAmmo = GetComponent<Gun>();
 }
     

 public void Update()
 {
     ammoBar.value = gunn.ammo;

} }

public class Gun : MonoBehaviour {

 public int ammo;
 public Transform muzzle;
 public Projectile projectile;
 public float msBetweenShots = 100;
 public float muzzleVelocity = 35;
 GunController gun;
 float nextShotTime;

 public void Start()
 {
     ammo = 20;
 }

 

 public void Shoot()
 {

     {
         if (Time.time > nextShotTime)
         {
             if (ammo >= 1)
             {
                 ammo--;

                 nextShotTime = Time.time + msBetweenShots / 1000;
                 Projectile newProjectile = Instantiate(projectile, muzzle.position, muzzle.rotation) as Projectile;
                 newProjectile.SetSpeed(muzzleVelocity);


             }
         }
     }
 }

}

public class GunController : MonoBehaviour { public Transform weaponHold; public Gun startingGun; Gun equippedGun;

 void Start()
 {
     if (startingGun != null)
     {
         EquipGun(startingGun);
     }
     
 }

 public void EquipGun(Gun gunToEquip)
 {
     if (equippedGun != null)
     {
         Destroy(equippedGun.gameObject);
     }
     equippedGun = Instantiate(gunToEquip, weaponHold.position, weaponHold.rotation) as Gun;
     equippedGun.transform.parent = weaponHold;
 }


 
 public void Shoot()
 {
     if (equippedGun != null)
     {
         equippedGun.Shoot();
         
     }
 }

}