public void LoadPDF()
    {
        if (!isLoading)
        {
            isLoading = true;

            Thread thread = new Thread(() =>
            {
                PDFManager.ConvertPDF(pathPDF, pathSave, firstPage, lastPage, width, height);
                isThreadEnd = true;
            });

            thread.Start();

            StartCoroutine(EndLoadPDF());
        }
    }