How can I add multiplayer function in my Offline Chess game

Hello I was coverting An Offline Chess Game into multiplayer game using photon pun plugin and I am not able to change it into multiplyer so can you help with me can you please suggest the next step of this script . how can I Instantiate Chess piece in this script (Sorry for incorrect english).

SCRIPT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!

using System.Collections; using System.Collections.Generic; using UnityEngine; using Photon.Pun; using UnityEngine.SceneManagement; using UnityEngine.UI;

public class Game : MonoBehaviourPunCallbacks { //Reference from Unity IDE public GameObject chesspiece;

//Matrices needed, positions of each of the GameObjects
//Also separate arrays for the players in order to easily keep track of them all
//Keep in mind that the same objects are going to be in "positions" and "playerBlack"/"playerWhite"
private GameObject[,] positions = new GameObject[8, 8];
private GameObject[] playerBlack = new GameObject[16];
private GameObject[] playerWhite = new GameObject[16];
//current turn
private string currentPlayer = "white";
//Game Ending
private bool gameOver = false;
//Unity calls this right when the game starts, there are a few built in functions
//that Unity can call for you
public void Start()
{
if(base.photonView.Owner.IsMasterClient)
{
playerWhite = new GameObject[] { Create("white_rook", 0, 0), Create("white_knight", 1, 0),
Create("white_bishop", 2, 0), Create("white_queen", 3, 0), Create("white_king", 4, 0),
Create("white_bishop", 5, 0), Create("white_knight", 6, 0), Create("white_rook", 7, 0),
Create("white_pawn", 0, 1), Create("white_pawn", 1, 1), Create("white_pawn", 2, 1),
Create("white_pawn", 3, 1), Create("white_pawn", 4, 1), Create("white_pawn", 5, 1),
Create("white_pawn", 6, 1), Create("white_pawn", 7, 1) };
}
playerBlack = new GameObject[] { Create("black_rook", 0, 7), Create("black_knight",1,7),
Create("black_bishop",2,7), Create("black_queen",3,7), Create("black_king",4,7),
Create("black_bishop",5,7), Create("black_knight",6,7), Create("black_rook",7,7),
Create("black_pawn", 0, 6), Create("black_pawn", 1, 6), Create("black_pawn", 2, 6),
Create("black_pawn", 3, 6), Create("black_pawn", 4, 6), Create("black_pawn", 5, 6),
Create("black_pawn", 6, 6), Create("black_pawn", 7, 6) };
//Set all piece positions on the positions board
for (int i = 0; i < playerBlack.Length; i++)
{
SetPosition(playerBlack);
SetPosition(playerWhite);
}
}
public GameObject Create(string name, int x, int y)
{
GameObject obj = PhotonNetwork.Instantiate("chesspiece", new Vector3(0, 0, -1), Quaternion.identity);
Chessman cm = obj.GetComponent<Chessman>(); //We have access to the GameObject, we need the script
cm.name = name; //This is a built in variable that Unity has, so we did not have to declare it before
cm.SetXBoard(x);
cm.SetYBoard(y);
cm.Activate(); //It has everything set up so it can now Activate()
return obj;
}
public GameObject CreateBlackPlayer(string name, int x, int y)
{
GameObject obj = PhotonNetwork.Instantiate("chesspiece", new Vector3(0, 0, -1), Quaternion.identity);
Chessman cm = obj.GetComponent<Chessman>(); //We have access to the GameObject, we need the script
cm.name = name; //This is a built in variable that Unity has, so we did not have to declare it before
cm.SetXBoard(x);
cm.SetYBoard(y);
cm.Activate(); //It has everything set up so it can now Activate()
return obj;
}
public void SetPosition(GameObject obj)
{
Chessman cm = obj.GetComponent<Chessman>();
//Overwrites either empty space or whatever was there
positions[cm.GetXBoard(), cm.GetYBoard()] = obj;
}
public void SetPositionEmpty(int x, int y)
{
positions[x, y] = null;
}
public GameObject GetPosition(int x, int y)
{
return positions[x, y];
}
public bool PositionOnBoard(int x, int y)
{
if (x < 0 || y < 0 || x >= positions.GetLength(0) || y >= positions.GetLength(1)) return false;
return true;
}
public string GetCurrentPlayer()
{
return currentPlayer;
}
public bool IsGameOver()
{
return gameOver;
}
public void NextTurn()
{
if (currentPlayer == "white")
{
currentPlayer = "black";
}
else
{
currentPlayer = "white";
}
}
public void Update()
{
if (gameOver == true && Input.GetMouseButtonDown(0))
{
gameOver = false;
//Using UnityEngine.SceneManagement is needed here
SceneManager.LoadScene("Game"); //Restarts the game by loading the scene over again
}
}

public void Winner(string playerWinner)
{
gameOver = true;
//Using UnityEngine.UI is needed here
GameObject.FindGameObjectWithTag("WinnerText").GetComponent<Text>().enabled = true;
GameObject.FindGameObjectWithTag("WinnerText").GetComponent<Text>().text = playerWinner + " is the winner";
GameObject.FindGameObjectWithTag("RestartText").GetComponent<Text>().enabled = true;
}