Slim Framework set name for PDF

I do not get pdf name set while downloading the PDF From Slim Framework As I have Assigned the name for pdf Through PDF Set Options

Like This:

<?php
    $pdf->writeHTMLCell(0, 0, '', '', $html, 0, 1, 0, true, '', true);
    $response = $this->response->withHeader('Content-type', 'application/pdf');
    $response->write($pdf->Output('My_cool_PDF.pdf', 'S'));
?>

But the file is getting downloaded by assigning name of the route name passed through html.

Example Url : http://localhost:8080/collections/getBranchWisePDF/1

if param is set 1 the filename is 1 which is assigned to pdf and the file gets downloaded

any options to change the pdf name using TCP Pdf and Slim Framework.

Thanks in advance