Scriptum/Assets/Scripts/RespawnScript.cs

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

public class RespawnScript : MonoBehaviour
{
    private string currentScene;

    public GameObject mainCh;
    public FloatValue maxHealth;

    public void RespawnOnCurrentScene()
    {
        mainCh = GameObject.FindGameObjectWithTag("Player");
        Scene scene = SceneManager.GetActiveScene();
        currentScene = scene.name;
        SceneManager.LoadScene(currentScene);

        Player player = mainCh.GetComponent<Player>();

        // 1. health
        player.currentHealth = PlayerPrefs.GetFloat("maxHealth");
        PlayerPrefs.SetFloat("health", PlayerPrefs.GetFloat("maxHealth"));
        PlayerPrefs.SetFloat("health-S", PlayerPrefs.GetFloat("maxHealth"));

        // 2. exp & lvl
        player.ManageLevels(PlayerPrefs.GetFloat("exp-S"));
    }
}