Instantiating a GameObject from a ScriptableObject

Hi, I am currently working on a system where the main character can summon/instantiate AI from a library, which is held in a scriptableObject. I get a NullRefExeption error.

This is the scriptable object.

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class DatabaseOfMinions : ScriptableObject {
 
     public Minions[] minions;
 
 }
     //what is in our database
     [System.Serializable]
     public class Minions
     {
         public string name;
         public GameObject prefab;
         public Sprite prefabSprite;
         public Rigidbody body;
 
         public int minionIndex;
         public int damageBlockingIndex;
 
         public float health;
         public float detectionRadius;
         public float attackRadius;
         public float attackDamage;
         public float speed;
         public float jumpHeight;
 
     }
 

This is the script that i use to instantiate:

 using UnityEngine;
 using System.Collections;
 
 public class MinionsSummoningManagerScript : MonoBehaviour {
 
     public DatabaseOfMinions database;
     //public Transform spawnPositionOnLeft;
     public Transform spawnPositionOnRight;
 
     public bool canSummon = true;
 
     void Awake()
     {
         if (!database)
         {
             database = Resources.Load("MinionDatabase") as DatabaseOfMinions;
         }
     }
 
     
     // Update is called once per frame
     void Update () {
 
         if (Input.GetKeyDown("a"))
         {
             if (canSummon)
             {
                 GameObject obj = Instantiate(database.minions[1].prefab, spawnPositionOnRight.transform.position, Quaternion.identity) as GameObject;
             }
         }
     
     }
 }

Any help would be much appreciated. Thank you :).