how do i change a bool from a script in a different game object c#

i am making a 2d platform game in the game there is a player a key and chest

i have labelled the key with the tag "chestKey"

i have a script on the chest called "ChestKey" and a script on the player called player interaction.

in the chestKey script i have a public bool called GotKey

i want to change that bool to true from the player interaction script using ontriggerenter2d

 public class ChestKey : MonoBehaviour {
 
     public LevelManager LevelManager;
     public int chestPoints = 250;
 
    public bool GotKey ;
     
 
 
 
     // Use this for initialization
     void Start ()
     {
         GameObject.FindGameObjectsWithTag("Player");
         GameObject.FindGameObjectsWithTag("chestKey");
         GotKey = false;
     }
 
 
     void OnTriggerEnter2D(Collider2D other)
     {
 
        
 
         if (other.tag == "Player" && GotKey)
         {
             Debug.Log("congratulations chest is open", gameObject);
             LevelManager.AddPoints(chestPoints);    
         }
 
         if (other.tag == "Player" && !GotKey)
         {
             Debug.Log("You Need the Key", gameObject);
         }
 
     }
     
 
 
 
 
     
 }
 

player interaction Script

 using UnityEngine;
 using System.Collections;
 using UnityEngine.SceneManagement;
 
 
 public class PlayerInteraction : MonoBehaviour
 {
 
     
     public LevelManager LevelManager;
     public HealthBar HealthBar;
 
     public int cogPoints = 10;
     public int gemPoints = 52;
 
     public GameObject Chest;
    public ChestKey chestKey;
 
     
     public Rigidbody2D rb;
 
     //reference to healthbar script so this script can find it
     void Start()
     {
        GameObject.FindGameObjectsWithTag("HealthBar");
 
         rb = GetComponent<Rigidbody2D>();
         chestKey = GameObject.Find("Chest").GetComponent<ChestKey>();
     }
 
  
 void OnTriggerEnter2D(Collider2D other)
     {
 
 
         Vector2 dir = transform.position - other.transform.position;
         dir.Normalize();
 
         if (other.tag == "chestKey")
         {
             Debug.Log("you have the key", gameObject);
           //  Chest.GetComponent<>;
         }
 
 
 
         //add cog points to score
         if (other.tag == "Cog")
         {
            
             LevelManager.AddPoints(cogPoints);
         }
 
 
         //add gem points to score
         if (other.tag == "Gem")
         {
            
             LevelManager.AddPoints(gemPoints);
         }
 
       
 
         //Health pick up add 40 to health
         if (other.tag == "Health")
         {
             HealthBar.curHealth += 40;
             
         }
 
         // NME takes health of player
         if (other.tag == "NME")
         {
             HealthBar.curHealth -= 10;
             //makes player bounce if hit by enemy
             Rigidbody2D rbOther = this.gameObject.GetComponent<Rigidbody2D>();
             rbOther.AddForce(dir * 1500 );// *Time.deltaTime);
            // Debug.Log(rbOther);
         }
         // if current health = 0 load gameover screen
         if (HealthBar.curHealth == 0)
         {
             SceneManager.LoadScene(1);
 
         }
     }
 }
 

i cant seem to get the reference right can anyone help?