Laravel : How download custom blade table as excel - excel

Question

I have this table in blade file in laravel app:
<form method="POST" action="{{url('/download')}}" id="download_form">
#csrf <!-- {{ csrf_field() }} -->
<table class="table font-weight-bold w-100" id="excel_table">
<thead class="table-primary">
<tr>
<th class="text-center">#</th>
<th class="text-center">ناڤ</th>
<th class="text-center">كوم</th>
</tr>
</thead>
<tbody>
<tr>
<td class="text-center">{{$counter}}</td>
<td class="text-right table-primary">{{$student->name}}</td>
<td class="text-center table-primary">{{$sub_total}}</td>
</tr>
</tbody>
</table>
<div>
<input type="hidden" name="file_contente" id="file_contente">
<input type="hidden" value="{{$stage}}" name="stage" id="">
<input type="hidden" value="{{$group}}" name="group" id="">
<button type="submit" id="download" class="btn btn-success">Download to excel</button>
</div>
</form>
</div>
<script>
$(document).ready(function() {
$('#download').click(function() {
var table_content = '<table>';
table_content += $('#excel_table').html();
table_content+= '</table>';
$('#file_content').val(table_content);
$('#download_form').html();
})
})
</script>
the controller is :
public function download(Request $req)
{
$temporary_html_file = './tmp_html/' . time() . '.html';
file_put_contents($temporary_html_file, $req->file_contente);
$reader = IOFactory::createReader('Html');
$spreadsheet = $reader->load($temporary_html_file);
$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
$filename = $req->stage." ".$req->group . '.xlsx';
$writer->save($filename);
header('Content-Type: application/x-www-form-urlencoded');
header('Content-Transfer-Encoding: Binary');
header("Content-disposition: attachment; filename=\"".$filename."\"");
readfile($filename);
unlink($temporary_html_file);
unlink($filename);
}
I get error :
file_put_contents(./tmp_html/1634558222.html): failed to open stream:
No such file or directory
How can I solve it ? what is the mistake i did?
Edit
after I created the temp_html folder in public folder I get this error :
./tmp_html/1634560521.html is an Invalid HTML file.