How do I put a few more prefabs in here?

Question

C++ / C#

in short, it is necessary that random prefabs spawn, it will not work to throw a few scripts, then they will spawn very stupidly. help make it so that there would be 9 prefabs here and spawn random 1 or 2 at a time.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class RandomSpawn : MonoBehaviour
{
    [SerializeField] private GameObject prefab;
    [SerializeField] private Vector2 spawnRate;

    private IEnumerator Start()
    {
        while (true)
        {
            yield return new WaitForSeconds(Random.Range(spawnRate.x, spawnRate.y));
            var pos = new Vector2(Random.Range(-20, 20), Random.Range(13, 13));
            Instantiate(prefab, pos, Quaternion.identity);
        }
    }
}