player prefs don't work, no error, I have no idea what's happening

Questions & Answers
1

this is a health script.

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

public class health : MonoBehaviour
{
    public float Health = 100f;
    public float damage = 10f;
    public string Map;
    public Text text;
    public Slider slider;
    public GameObject Respawn;
    
    void start()
    {
        Respawn.SetActive(false);
        Health = PlayerPrefs.GetFloat("Health");
    }
    void Update()
    {
        PlayerPrefs.SetFloat("Health", Health);
        PlayerPrefs.Save();
        text.text = "" + Health;
        slider.value = Health;
        if (Health <= 0)
        {
            Die();
        }
    }

    public void OnTriggerEnter(Collider hit)
    {
        if (hit.GetComponent<Collider>().gameObject.tag == "zombie_L1")
        {
            Health -= 10f;
        }
    }
    void Die()
    {
        Respawn.SetActive(true);
        SceneManager.LoadScene(Map);
    }
}
2

Health = PlayerPrefs.GetFloat(“Health”);
PlayerPrefs.SetFloat(“Health”, Health);
PlayerPrefs.Save();

This way, when the script starts, it will immediately retrieve the value of “Health” from PlayerPrefs and save it to the Health variable. Also, make sure that you are setting the value of “Health” in PlayerPrefs before trying to retrieve it.