Fatal error: Uncaught Error: Class "PhpOffice\PhpSpreadsheet\Writer\Html" not found in C:\xampp\htdocs\xlsss\PhpSpreadsheet-master\src\PhpSpreadsheet\Writer\Pdf.php:10 Stack trace: #0 {main} thrown in C:\xampp\htdocs\xlsss\PhpSpreadsheet-master\src\PhpSpreadsheet\Writer\Pdf.php on line 10