Collector.cs

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;

public class Collector : MonoBehaviour
{
    private int score;

    public int goal;
    public string objectTag;
    public Text textWindow;
    public UnityEvent GoalAchieved;


    private void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.CompareTag(objectTag))
        {
            score++;
            textWindow.text = score.ToString();
            other.gameObject.SetActive(false);

            if (score == goal) GoalAchieved.Invoke();
        }
    }
}