what has gone wrong with this script

i have a problem with this code i got from a you tube tutorial i copied the code from the linked repository and renamed one script from worldgen to voxelterrain but i get this error

NullReferenceException: Object reference not set to an instance of an object Player.Start () (at Assets/scripts/Player.cs:10)

i looked at the code and the tutorials to try to figure out what was wrong but the youtuber does not actualy make anything called World in his videos ill put the voxelterrain script up for reference as well as the offending script

player script(offending)

  using UnityEngine;
     using System.Collections;
     
     public class Player : MonoBehaviour
     {
         VoxelTerrain world;
         
         void Start()
         {
             world = (VoxelTerrain)GameObject.Find("World").GetComponent(typeof(VoxelTerrain));
         }
         
         void Update()
         {
             if(Input.GetMouseButton(0))
             {
                 RaycastHit hit;
                 Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
                 if(Physics.Raycast(ray, out hit))
                 {
                     BreakBlock(BlockAtPoint(hit.point));
                 }
             }
         }
         
         Voxel BlockAtPoint(Vector3 point)
         {
             Debug.Log("X: " + FloatToInt(point.x) + " Y: " + FloatToInt(point.y) + " Z: " + FloatToInt(point.z));
             return world.chunk.voxels[FloatToInt(point.x),FloatToInt(point.y),FloatToInt(point.z)];
         }
         
         void BreakBlock(Voxel block)
         {
             block.type = 0;
         }
         
         int FloatToInt(float value)
         {
             float dec =  (int)value - value;
             if(dec < 0.5)
             {
                 float num = value - dec;
                 return (int)num;
             }
             else
             {
                 return (int)value;
             }
         }
     }

Voxelterrain script

 using UnityEngine;
 using System.Collections;
 
 public class VoxelTerrain : MonoBehaviour
 {
     Chunk CHNK;
     public Chunk chunk {
         get {return CHNK;}
         set {CHNK = value;}
     }
     public string test = "Hello World!";
     
     void Start()
     {
         chunk = new Chunk();
     }
     
     void Update()
     {
         chunk.Update();
     }
 }