rabidus-test/Assets/EnergyText.cs

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

public class EnergyText : MonoBehaviour
{
    private EnergyController _energyController;
    private TMPro.TextMeshProUGUI _text;

    private void Awake()
    {
        _energyController = FindObjectOfType<EnergyController>();
        _text = GetComponent<TMPro.TextMeshProUGUI>();
    }

    private void OnEnable()
    {
        _energyController.OnEnergyChange += UpdateText;
    }

    private void OnDisable()
    {
        _energyController.OnEnergyChange -= UpdateText;
    }

    private void UpdateText(float energy)
    {
        _text.SetText(energy.ToString());
    }
}