My teacher gave me a challenge in unity (c#) where I have to load prefabs into an array (as a GameObject[] function). The code I have works in the editor, but when I build the game, it gives me the error The name "Asset Database" does not exist in the curernt context. The code I have currently is:

using System.Collections.Generic;
using System.IO;
using UnityEngine;
using UnityEditor;
using System;

public class FindCards : MonoBehaviour
{
    public string directoryName;
    public List<GameObject> foundGameObjects;

    public GameObject[] ListOfCards()
    {
        // get the directory and the files in them
        DirectoryInfo dirInfo = new DirectoryInfo(Application.dataPath + directoryName);

        FileInfo[] fileInfo = dirInfo.GetFiles("*.prefab");

        // loop through the files
        foreach(FileInfo file in fileInfo)
        {
            // get the path to the directory again (with proper formatting)
            string fullPath = file.FullName.Replace(@"\","/");
            string assetPath = "Assets" + fullPath.Replace(Application.dataPath, "");
    
    
            GameObject _asset;
            // load the asset from the direcotry
            _asset = AssetDatabase.LoadAssetAtPath(assetPath, typeof(GameObject)) as GameObject;            

            // add it to the list
            foundGameObjects.Add(_asset);
            Debug.Log(_asset.name);
        }


        // return the list as an array
        return(foundGameObjects.ToArray());
    }

    public void SetCardProperties(string cardName, Card card)
    {
        // get the first string, and the int
        // from the card's name
        string[] sub = cardName.Split('_');

        // (if the name was Diamond_07,     // string name
        // there would be an int = 07 and   // name[0]
        // a string = Diamond)              // name[1]
        card.suit = sub[0];
        Int32.TryParse(sub[1], out card.number);
    }
}

The code that is calling this function looks like this (note that this is in a different script):

private void Start()
{
    canScore = true;
    gameIsGoing = true;

    // set up cards
    cards = findCards.ListOfCards();

    for (int i = 0; i < cards.Length; i++)
    {
        Card card = cards[i].GetComponent<Card>();

        findCards.SetCardProperties(cards[i].name, card);
    }

    // set up deck
    ResetDeck();
}

The directory here: Prefabs in the directory

Errors here: Errors unity gives me

I have been pulling my hair out, because there was nothing online I could find that would help me. My teacher gave this to me as challenge because he also did not know how to do it which is why I'm asking this question...

Thanks in advance!