Aspose export to excel watermark

there is always a watermark when exporting to excel with aspose, and the license files without watermarking on the Internet are all the same. An effective way to remove the watermark

public  void excel2sql1() {
        if (!getLicense()) {          // License 
        }
        try {
                File pdfFile = new File("D:/aspose/cs123.xls");// 
                Workbook workbook = new Workbook(); //
                Worksheet sheet = workbook.getWorksheets().get(0); //
                Cells cells = sheet.getCells();//
                cells.get(0,0).putValue("123455");


                FileOutputStream fileOS = new FileOutputStream(pdfFile);
                workbook.save(fileOS, SaveFormat.XLSX);
                fileOS.close();
        } catch (Exception e) {
                e.printStackTrace();
        }
    }

public static boolean getLicense() {
        boolean result = false;
        try {
            InputStream is = Test.class.getClassLoader().getResourceAsStream("license.xml"); //  license.xml..\WebRoot\WEB-INF\classes
            License aposeLic = new License();
            aposeLic.setLicense(is);
            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

<License>
  <Data>
    <Products>
      <Product>Aspose.Total for Java</Product>
      <Product>Aspose.Words for Java</Product>
    </Products>
    <EditionType>Enterprise</EditionType>
    <SubscriptionExpiry>20991231</SubscriptionExpiry>
    <LicenseExpiry>20991231</LicenseExpiry>
    <SerialNumber>8bfe198c-7f0c-4ef8-8ff0-acc3237bf0d7</SerialNumber>
  </Data>
  <Signature>sNLLKGMUdF0r8O1kKilWAGdgfs2BvJb/2Xp8p5iuDVfZXmhppo+d0Ran1P9TKdjV4ABwAgKXxJ3jcQTqE/2IRfqwnPf8itN8aFZlV3TJPYeD3yWE7IT55Gz6EijUpC7aKeoohTb4w2fpox58wWoF3SNp6sK6jDfiAUGEHYJ9pjU=</Signature>
</License>