Fatal error: Uncaught Error: Class "FontLib\Header" not found in /var/www/html/upload/PhpSpreadsheet-master/vendor/dompdf/php-font-lib/src/FontLib/EOT/Header.php:20 Stack trace: #0 {main} thrown in /var/www/html/upload/PhpSpreadsheet-master/vendor/dompdf/php-font-lib/src/FontLib/EOT/Header.php on line 20