Kill, Double Kill, Triple Kill! How I put this in the game?

Hi people, I made a script to put a kill, Double Kill, Triple Kill (voice) in the game. However Doesn´t work... Someone can help me, writing a right script for me! Below is the script I made. Thanks!

 using UnityEngine;
 using UnityEngine.Networking;
 using System.Collections;
 
 [RequireComponent(typeof(PlayerSetup))]
 public class Player : NetworkBehaviour {
 
     [SyncVar]
     private bool _isDead = false;
     public bool isDead
     {
         get { return _isDead; }
         protected set { _isDead = value; }
     }
 
     [SerializeField]
     private int maxHealth = 100;
 
     [SyncVar]
     private int currentHealth;
 
     public float GetHealthPct ()
     {
         return (float)currentHealth / maxHealth;
     }
 
     [SyncVar]
     public string username = "Loading...";
 
     public int kills;
     public int deaths;
 
     [SerializeField]
     private Behaviour[] disableOnDeath;
     private bool[] wasEnabled;
 
     [SerializeField]
     private GameObject[] disableGameObjectsOnDeath;
 
     [SerializeField]
     private GameObject deathEffect;
 
     [SerializeField]
     private GameObject spawnEffect;
 
     private bool firstSetup = true;
 
 
     public AudioSource audioPlayer;
     public AudioClip[] killStreakSounds;
     int currentStreak = 0;
     float killTimer = 0;
     const float streakReset = 1;
 
     public void SetupPlayer ()
     {
         if (isLocalPlayer)
         {
             //Switch cameras
             GameManager.instance.SetSceneCameraActive(false);
             GetComponent<PlayerSetup>().playerUIInstance.SetActive(true);
         }
 
         CmdBroadCastNewPlayerSetup();
     }
 
     [Command]
     private void CmdBroadCastNewPlayerSetup ()
     {
         RpcSetupPlayerOnAllClients();
     }
 
     [ClientRpc]
     private void RpcSetupPlayerOnAllClients ()
     {
         if (firstSetup)
         {
             wasEnabled = new bool[disableOnDeath.Length];
             for (int i = 0; i < wasEnabled.Length; i++)
             {
                 wasEnabled[i] = disableOnDeath[i].enabled;
             }
 
             firstSetup = false;
         }
 
         SetDefaults();
     }
 
     //void Update()
     //{
     //   if(KillTimer > 0)
     //   {
     //      KillTimer -= Time.deltaTime;
     //      if(KillTimer <= 0) ResetStreak();
     //   }
 
     //    if (!isLocalPlayer)
     //        return;
 
     //    if (Input.GetKeyDown(KeyCode.K))
     //    {
     //        RpcTakeDamage(99999);
     //    }
     //}
 
 [ClientRpc]
     public void RpcTakeDamage (int _amount, string _sourceID)
     {
         if (isDead)
             return;
 
         currentHealth -= _amount;
 
         Debug.Log(transform.name + " now has " + currentHealth + " health.");
 
         if (currentHealth <= 0)
         {
             Die(_sourceID);
         }
     }
 
     private void Die(string _sourceID)
     {
         
     isDead = true;
 
         Player sourcePlayer = GameManager.GetPlayer(_sourceID);
         if (sourcePlayer != null)
         {
             sourcePlayer.kills++;
             GameManager.instance.onPlayerKilledCallback.Invoke(username, sourcePlayer.username);
         }
 
         deaths++;
 
         //Disable components
         for (int i = 0; i < disableOnDeath.Length; i++)
         {
             disableOnDeath[i].enabled = false;
         }
 
         //Disable GameObjects
         for (int i = 0; i < disableGameObjectsOnDeath.Length; i++)
         {
             disableGameObjectsOnDeath[i].SetActive(false);
         }
 
         //Disable the collider
         Collider _col = GetComponent<Collider>();
         if (_col != null)
             _col.enabled = false;
 
         //Spawn a death effect
         GameObject _gfxIns = (GameObject)Instantiate(deathEffect, transform.position, Quaternion.identity);
         Destroy(_gfxIns, 3f);
 
         //Switch cameras
         if (isLocalPlayer)
         {
             GameManager.instance.SetSceneCameraActive(true);
             GetComponent<PlayerSetup>().playerUIInstance.SetActive(false);
         }
 
         Debug.Log(transform.name + " is DEAD!");
 
         StartCoroutine(Respawn());
     }
 
     private IEnumerator Respawn ()
     {
         yield return new WaitForSeconds(GameManager.instance.matchSettings.respawnTime);
 
         Transform _spawnPoint = NetworkManager.singleton.GetStartPosition();
         transform.position = _spawnPoint.position;
         transform.rotation = _spawnPoint.rotation;
 
         yield return new WaitForSeconds(0.1f);
 
         SetupPlayer();
 
         Debug.Log(transform.name + " respawned.");
     }
 
     public void SetDefaults ()
     {
         isDead = false;
 
         currentHealth = maxHealth;
 
         //Enable the components
         for (int i = 0; i < disableOnDeath.Length; i++)
         {
             disableOnDeath[i].enabled = wasEnabled[i];
         }
 
         //Enable the gameobjects
         for (int i = 0; i < disableGameObjectsOnDeath.Length; i++)
         {
             disableGameObjectsOnDeath[i].SetActive(true);
         }
 
         //Enable the collider
         Collider _col = GetComponent<Collider>();
         if (_col != null)
             _col.enabled = true;
 
         //Create spawn effect
         GameObject _gfxIns = (GameObject)Instantiate(spawnEffect, transform.position, Quaternion.identity);
         Destroy(_gfxIns, 3f);
     }
 
     private void Die()
     {
        audioPlayer.PlayOneShot(killStreakSounds[currentStreak]);
        if (currentStreak < killStreakSounds.Length - 1) currentStreak++;
        killTimer = streakReset;
     }
 
     void ResetStreak() // Call this when your character dies
     {
        currentStreak = 0;
        killTimer = 0;
     }
 
        
 
 }