GUI trigger help (C#)

Hi Guys, I have had this problem for a while. Basiclly i am making 2d platform game and i am trying to make it so when the player hits the finish flag the gui show up. i already have a script for this but it never works i dont know why. FYI i have just started learning c#

Thank You

Script

using UnityEngine;
using System.Collections;
 
public class Level_Finish : MonoBehaviour {
 
    public GUITexture finishFlag;
 
    void Start () {
       finishFlag.enabled = false;
    }
 
    void OnTriggerEnter(Collider col){
       if (col.tag == "Player") {
         finishFlag.enabled = true;   
       }
    }
}

You need to put your GUI code in OnGui to render it. GUI Basics

using UnityEngine;
using System.Collections;
 
public class Level_Finish : MonoBehaviour {
 
    public Texture finishTexture;
	private bool bFinish = false;
 
    void Start () {
       bFinish = false;
    }
 
    void OnTriggerEnter(Collider col){
       if (col.tag == "Player") {
         bFinish = true;   
       }
    }
	
	void OnGui() {
		GUI.Box(new Rect(10,10,100,90), finishTexture);
	}
}