Fatal error: Uncaught Error: Class "tFPDF" not found in /var/www/html/upload/PhpSpreadsheet-master/vendor/setasign/fpdi/src/Tfpdf/FpdfTpl.php:20 Stack trace: #0 {main} thrown in /var/www/html/upload/PhpSpreadsheet-master/vendor/setasign/fpdi/src/Tfpdf/FpdfTpl.php on line 20