Procedural Generation Instantiating GameObjects

This might help. This is a script I wrote last fall which generates balls in a random location within a sphere. With just a little bit of adaptation I hope you can get it working for your purposes as well!

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class BallGenerator : MonoBehaviour {
 
     public GameObject ballPrefab;
     public Transform startPoint;
     public Transform endPoint;
 
     Vector3 tempVector = Vector3.zero;
     Vector3 randomStartPoint = Vector3.zero;
     Vector3 randomEndPoint = Vector3.zero;
 
     [ContextMenu ("GenerateBall()")]
     public void GenerateBall () {
 
         randomStartPoint = GenerateRandomPointFrom (startPoint.position);
         randomEndPoint = GenerateRandomPointFrom (endPoint.position);
 
         GameObject go = GameObject.Instantiate (ballPrefab, randomStartPoint, Quaternion.identity);
         Transform newTransform = new GameObject ().transform;
         newTransform.position = randomStartPoint;
         go.GetComponent<AnimationCurveBall> ().startPoint = newTransform;
         newTransform = new GameObject ().transform;
         newTransform.position = randomEndPoint;
         go.GetComponent<AnimationCurveBall> ().endPoint = newTransform;
 
     }
     private Vector3 GenerateRandomPointFrom(Vector3 source) {
         tempVector = Random.insideUnitSphere;
         tempVector = tempVector * 30f;
         return source + tempVector;
     }
 }
 

I hope it helps!