How can I create excel sheet column headers from array using phpspreadsheet library?
Below is the code I am trying but it's not working:
    // $header is an array containing column headers
    $header = array("Customer Number", "Customer Name", "Address", "City", "State", "Zip");
    $spreadsheet = new Spreadsheet();
    $sheet = $spreadsheet->getActiveSheet();
    $sheet->fromArray($header, NULL, 'A1');     
    // redirect output to client browser
    header('Content-Type: application/vnd.ms-excel');
    header('Content-Disposition: attachment;filename="myfile.xlsx"');
    header('Cache-Control: max-age=0');
    $writer = new Xlsx($spreadsheet);
    $writer->save('php://output');