尝试在CodeIgniter 3中使用Phpencil Sheet导出xlsx文件。当我运行URL时，它显示无法访问该网站。网站可能暂时关闭，或者它可能已永久移动到一个新的网址。

控制器

require 'vendor/autoload.php';
                
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

function generateLR(){
                    // create file name
  header('Content-Type: application/vnd.ms-excel');
  header('Content-Disposition: attachment;filename="result.xlsx');
  header('Cache-Control: max-age=0');
  $spreadsheet = new Spreadsheet();
  $sheet = $spreadsheet->getActiveSheet();
  $sheet->setCellValue('A1', 'Hello World !');
  $writer = new Xlsx($spreadsheet); 
  $writer->save('php://output');
}

但是如果我尝试在本地保存$writer->save('hello world.xlsx');。输出成功保存到项目文件夹中。
也尝试使用IOFactory，但结果是一样的：网站暂时关闭

require 'vendor/autoload.php';
                
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\IOFactory;

function generateLR(){
                    // create file name
  header('Content-Type: application/vnd.ms-excel');
  header('Content-Disposition: attachment;filename="result.xlsx');
  header('Cache-Control: max-age=0');
  $spreadsheet = new Spreadsheet();
  $sheet = $spreadsheet->getActiveSheet();
  $sheet->setCellValue('A1', 'Hello World !');
  $writer = IOFactory::createWriter($spreadsheet,'Xlsx');
  $writer->save('php://output');
}

错误图片

是否存在env问题？