LevelLoader.cs

using UnityEngine;
using UnityEngine.SceneManagement;

public class LevelLoader : MonoBehaviour
{
    private bool playerInZone;


    public string levelToLoad;



    void Start()
    {
        playerInZone = false;
    }

    void Update()
    {
        if (Input.GetAxisRaw("Vertical") > 0 && playerInZone)//&& Input.GetKey(KeyCode.W))
        {
            // Load the level when 'W' key is pressed and player is in the zone
            //Application.LoadLevel(levelToLoad);// Load the level gives warning dude to update
            SceneManager.LoadScene(levelToLoad);// Load the level gives error for SceneManager



        }
    }

    void OnTriggerEnter2D(Collider2D other)
    {
        if (other.name == "Player")
        {
            // Set playerInZone to true when the player enters the trigger zone
            playerInZone = true;
        }
    }

    void OnTriggerExit2D(Collider2D other)
    {
        if (other.name == "Player")
        {
            // Set playerInZone to false when the player exits the trigger zone
            playerInZone = false;
        }
    }
}