Anyone knows how to refresh tiles?

Hi, i'm creating my very first videogame, and i've come across a problem i can't solve.

It's a 2d pixel art game, in which you solve puzzles. The problem is that, to solve a puzzle, u have to press some buttons, and they should obviously change. Basically, there's a Circle Collider and when the player hits it, the trigger should change the tile at the player's position.

The main point is that i have a tile in a tilemap which i want to exchange by another sprite outside that tilemap.

I've tried to use a function called RefreshTile, but it doesn't work (maybe it's because i don't know how to make it work). Can anyone give me an alternative to that or just explain me how to use RefreshTile??

This is the code i'm using: using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.Tilemaps;

 public class FirstRoom : MonoBehaviour
 {
     public GameObject Snicket;
     public GameObject Warp;
     public Animator door;
 
     public Tilemap firstRoom;
     public Tile buttonON;
     public ITilemap buttonOn;
     public Sprite on;
 
     float buttonPressed;
 
 
     // Use this for initialization
     void Start()
     {
         firstRoom = GetComponentInChildren<Tilemap>();
         door = GetComponentInChildren<Animator>();
         buttonPressed = 0;
 
         Warp.GetComponentInChildren<BoxCollider2D>().enabled = false;
     }
 
     // Update is called once per frame
     void Update()
     {
         if (buttonPressed == 4)
         {
             // Debug.Log("Hocus Fucking Pocus get this bitch openus");
             door.SetBool("Open", true);
             Warp.GetComponent<Collider2D>().enabled = true;
         }
     }
 
     private void OnTriggerEnter2D(Collider2D collision)
     {
         Vector3Int buttonPosition = new Vector3Int((int)Snicket.transform.position.x, (int)Snicket.transform.position.y, (int)Snicket.transform.position.z);
 
         Vector3 asdf = new Vector3(Snicket.transform.position.x, Snicket.transform.position.y, Snicket.transform.position.z);
 
         if (collision.tag == "Snicket")
         {
             // Debug.Log("clonk");
 
             GetComponent<CircleCollider2D>().enabled = false;
 
             firstRoom.GetTile(buttonPosition).RefreshTile(buttonPosition, /*   WHAT THE HELL DO I WRITE HERE   */);
 
 
             buttonPressed++;
         }
     }
 }