Prefab spawner doesnt work

So i am pretty new on Unity and i found this tutorial

https://www.youtube.com/watch?v=HIsEqKPoJXM&list=PLLH3mUGkfFCXps_IYvtPcE9vcvqmGMpRK∈dex=7

and i tried to make the same process on my android game project but nothing happened.I think my problem is about the cylinder.Because i am using cylinder instead of tile.I will be so glad if you guys help me.Here is my map;

[url=https://hizliresim.com/XEoDz6][img]https://i.hizliresim.com/XEoDz6.png[/img][/url]

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class CylinderManager : MonoBehaviour 
 {
     public GameObject[] cylinderPrefabs;
 
     private Transform playerTransform;
     private float spawnZ = 0.0f;
     private float cylinderLength = 30.0f;
     private int amnCylindersOnScreen = 7;
 
 
 
     // Use this for initialization
     private void Start () {
 
         playerTransform = GameObject.FindGameObjectWithTag ("Player").transform;
 
         for (int i = 0; i < amnCylindersOnScreen; i++) 
         {
             SpawnTile ();
         }
     }
     
     // Update is called once per frame
     private void Update () {
         if (playerTransform.position.z > (spawnZ - amnCylindersOnScreen * cylinderLength)) 
         {
             SpawnTile ();
         }
         
     }
 
     private void SpawnTile(int prefabIndex = -1)
     {
         GameObject go;
         go = Instantiate (cylinderPrefabs [0]) as GameObject;
         go.transform.SetParent (transform);
         go.transform.position = Vector3.forward * spawnZ;
         spawnZ += cylinderLength;
     }
 }
 

SOLUTION

https://forum.unity.com/posts/3239646/