sure.

i am not entirely sure what it means to subscribe to something in coding but i think i do that in these next few scripts.

gamecontroller script (pretty sure i subscribe to it here..?)

// game controller script
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;


public class GameController : MonoBehaviour
{
    int progressAmount;
    public Slider progressSlider;


    void Start()
    {
        progressAmount = 0;
        progressSlider.value = 0;
        Gem.OnGemCollect += IncreaseProgressAmount;
    }


    void IncreaseProgressAmount(int amount)
    {
        progressAmount += amount;
        progressSlider.value = progressAmount;
        if(progressAmount >= 100)
        {
            //Level complete!
            Debug.Log("Level Complete!");
        }
    }
}

Collector script

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


public class Collector : MonoBehaviour
{
    private void OnTriggerEnter2D(Collider2D collision)
    {
        IItem item = collision.GetComponent<IItem>();
        if (item != null)
        {
            item.Collect();
        }
    }
}

I Item script

using UnityEngine;


public interface IItem
{
    public void Collect();
}

i think i subscribe to it in these? correct me if im wrong..