EOSUnlockAchievement

using System;
using System.Collections;
using System.Collections.Generic;

using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

using Epic.OnlineServices;
using Epic.OnlineServices.Achievements;
using Epic.OnlineServices.Ecom;
using Epic.OnlineServices.UI;
using Epic.OnlineServices.Stats;

using PlayEveryWare.EpicOnlineServices;
using PlayEveryWare.EpicOnlineServices.Samples;

public class EOSUnlockAchievement : MonoBehaviour
{
    private EOSAchievementManager achievementManager;
    private EOSLeaderboardManager statManager;

    private void Awake()
    {
        var achievementManager = EOSManager.Instance.GetOrCreateManager<EOSAchievementManager>();
        var statManager = EOSManager.Instance.GetOrCreateManager<EOSLeaderboardManager>();
    }

    public void UnlockAchievement(string achievementID)
    {
        achievementManager = EOSManager.Instance.GetOrCreateManager<EOSAchievementManager>();
        achievementManager.UnlockAchievementManually(achievementID);
        Debug.Log("Epic achievement unlocked");
    }

    public void IncrementStat(string whichStat, int howMuch)
    {
        statManager = EOSManager.Instance.GetOrCreateManager<EOSLeaderboardManager>();
		// The different types of stat on Epic are:
		// SUM: adds the value in 'howMuch' to the existing stat total
		// MAX: takes whichever is bigger from either 'howMuch' or the existing stat
		// MIN: takes whichever is smaller from either 'howMuch' or the existing stat
		// LATEST: cannot be used for achievements
        statManager.IngestStat(whichStat, howMuch);
        Debug.Log("Epic stat updated");
    }
}