Assets/Scripts/HealthBar.cs

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

public class HealthBar : MonoBehaviour
{
    private Slider slider;
    public Text healthCounter;
    public GameObject playerState;

    private float currentHealth, maxHealth;
    // Start is called before the first frame update
    void Awake()
    {
        slider = GetComponent<Slider>();
        
    }

    // Update is called once per frame
    void Update()
    {
        currentHealth = playerState.GetComponent<PlayerState>().currentHealth;
        maxHealth = playerState.GetComponent<PlayerState>().maxHealth;

        float fillValue = currentHealth/maxHealth;
        slider.value = fillValue;
        healthCounter.text = currentHealth+"/"+maxHealth;

    }
}