تحويل XLTX إلى XLS

// For complete examples and data files, please go to https://github.com/aspose-cells-cloud/aspose-cells-cloud-php/
    <?php
    require_once('vendor\autoload.php');
    use \Aspose\Cells\Cloud\Api\CellsApi;
    $instance = new CellsApi(getenv("ProductClientId"),getenv("ProductClientSecret"));
    $path ='Book1.xltx';    
    $format ='xls';
    $password = null;
    $outPath = null;      
    $result = $this->instance->cellsWorkbookPutConvertWorkBook($path ,$format, $password,  $outPath);
    $size = $result->getSize();
    $content  = $result->fread($size);
    $file = fopen("destfile.xls", 'w');
    fwrite($file,$content);
    fclose($file);