❔ My Level Number keep returning as 0 (Unity)

   int levelNu;

    void Update()
    {
        Debug.Log(levelNu);
    }

    public void LoadNextScene()
    {
        int currentSceneIndex = SceneManager.GetActiveScene().buildIndex;
        int nextSceneIndex;
        nextSceneIndex = ++currentSceneIndex;
        if (currentSceneIndex == SceneManager.sceneCountInBuildSettings)
        {
            nextSceneIndex = 0;
        }
        SceneManager.LoadScene(nextSceneIndex);
        levelNu = currentSceneIndex;
    }