Why don't the Prefabs in my GameObject appear?

Hello, everyone. I am still learning how to use Unity. I am trying to create a Randomizer that randomly spawns a group of Peaches. I noticed that when I place the Prefabs for the Peaches in the Spawner, the Randomizer works; however, when I place the GameObjects that contain the Prefabs for the Peaches in the Spawner, the Randomizer does not work. Could someone provide a solution to the issue then explain what was causing the issue? Thank you.

The Code that I am using:

using System.Collections; using System.Collections.Generic; using UnityEngine; public class PeachSpawner : MonoBehaviour { public List spawnObjects = new List();

 public float timeToSpawn; 

 private float currentTimeToSpawn;

 public bool isTimer;

 public bool isRandomized; 


 // Start is called before the first frame update
 void Start()
 {
     currentTimeToSpawn = timeToSpawn; 
 }

 // Update is called once per frame
 void Update()
 {
     if (isTimer)
     {
         updateTimer();
     }
 } 

 private void updateTimer()
 {
     if (currentTimeToSpawn > 0)
     {
         currentTimeToSpawn -= Time.deltaTime; 
     }

     else
     {
         SpawnObject();
         currentTimeToSpawn = timeToSpawn;
     }
 }

 public void SpawnObject()
 {
     int index = isRandomized ? Random.Range(0, spawnObjects.Count) : 0; 
     if (spawnObjects.Count > 0)
     {
         Instantiate(spawnObjects[index], transform.position, Quaternion.identity); 
     } 
 }

}