GetComponent.sprite is not valide. please help

Hi, I'm trying to make a game.

I have a database in Json and I'm trying to get an item from my database to my inventory but I can't get the sprite because GetComponent.sprite is not valid for me.

here is my code. please help

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class InventaireChamp : MonoBehaviour {
 
     GameObject panelChoix;
     GameObject slotChoix;
     ChampDatabase database;
     public GameObject choixSlot;
     public GameObject choixChamp;
 
     int nbSlot;
     public List<Champ> champs = new List<Champ>();
     public List<GameObject> slots = new List<GameObject>();
 
     void Start()
     {
         database = GetComponent<ChampDatabase>();
 
         nbSlot = 14;
         panelChoix = GameObject.Find("Inventory");
         slotChoix = panelChoix.transform.Find("SlotChoix").gameObject;
         for (int i = 0; i < nbSlot; i++)
         {
             champs.Add(new Champ());
             slots.Add(Instantiate(choixSlot));
             slots[i].transform.SetParent(slotChoix.transform);
         }
 
         AddChamp(3);
     }
 
     public void AddChamp(int idCreature)
     {
         database = GetComponent<ChampDatabase>();
 
         Champ champToAdd = database.FetchChampByID(idCreature);
         Debug.Log(champToAdd.NomCreature);
         for (int i = 0; i < champs.Count; i++)
         {
             if (champs[i].IdCreature == -1)
             {
                 champs[i] = champToAdd;
                 GameObject champObj = Instantiate(choixChamp);
                 champObj.transform.SetParent(slots[i].transform);
                 Debug.Log(champToAdd.NomCreature);
                 champObj.GetComponent<Image>.sprite = champToAdd.Sprite;
                 champObj.transform.position = Vector2.zero;
                 break;
 
 
             }
         }
     }
 }