how to save a few ints into a game file using binary formatter

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using UnityEngine;

public class SaveNLoadManager : MonoBehaviour {
    public PlayerData pData;
    public MinerManager mManager;
    public StoneBank sBank;
    public void SaveData()
    {
        BinaryFormatter bf = new BinaryFormatter();
        FileStream stream = new FileStream(Application.persistentDataPath + "/player.sav", FileMode.Create);

        PlayerData data = new PlayerData();

        data.stats[0] = sBank.stoneperclick;
        data.stats[1] = sBank.stone;
        data.stats[2] = mManager.level;
        data.stats[3] = mManager.xp;
        data.stats[4] = mManager.maxXp;

        bf.Serialize(stream, data);
        stream.Close();
    }
    public void LoadData(){
        if(File.Exists(Application.persistentDataPath + "/player.sav"))
        {
            
            Stream stream = File.Open(Application.persistentDataPath + "/player" + ".sav", FileMode.Open);
            BinaryFormatter bf = new BinaryFormatter();
            PlayerData data = (PlayerData)bf.Deserialize(stream);

            stream.Close();
            sBank.stoneperclick = data.stats[0];
            sBank.stone = data.stats[1];
            mManager.level = data.stats[2];
            mManager.xp = data.stats[3];
            mManager.maxXp = data.stats[4];
        }
    }
}   

[Serializable]
public class PlayerData
    {
    public MinerManager mManager;
    public StoneBank sBank;
    public float[] stats;
    public PlayerData()
        {
         stats = new float[5];
        stats[0] = sBank.stoneperclick;
        stats[1] = sBank.stone;
        stats[2] = mManager.level;
        stats[3] = mManager.xp;
        stats[4] = mManager.maxXp;

        }
    }

There’s a tutorial here that explains using BinaryFormatter and FileStream to save and load data, Maybe that can help you.