How to make cheat code system like in GTA?

Thank you I tried it and it works

  using System.Collections;

using System.Collections.Generic; using UnityEngine;

public class cheatHackCode : $$anonymous$$onoBehaviour {

 private string[] cheatCode;
 private int index;
 public GameObject gun;
 void Start() {
     
     cheatCode = new string[] { "a", "b", "c", "d", "e" };
     index = 0;  
     gun.SetActive (false);
 }

 void Update() {
     
     if (Input.any$$anonymous$$eyDown) {
 
         if (Input.Get$$anonymous$$eyDown(cheatCode[index])) {
         
             index++;
         }
     
         else {
             index = 0;  
         }
     }


     if (index == cheatCode.Length) {
     
     gun.SetActive(true);
     }
 }

}

Just to clarify something i thought of afterwards. You could 'cheat' a little and use the Unity Text InputField, which is part of the UI stuff. Then the string etc is created for you in the varsomeinputField.text