phpoffice edit excel document

//Read the templatetemplate = 'file.xlxs';$objReader = IOFactory::load($template);$objReader->setActiveSheetIndex(0);$objPHPExcel = $objReader->getActiveSheet();$objPHPExcel->setCellValue('A' ,'aaa')->setCellValue('B', 'bbb');ob_end_clean();ob_start();$fileName = 'filename';header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');header('Content-Disposition: attachment;filename="' . $fileName . '"');header('Cache-Control: max-age=0');$writer = IOFactory::createWriter($objReader, 'Xlsx');$writer->save('php://output');