<?php
                  include  "../koneksi.php";
                  $no = 1;

                  $db = mysqli_query($conn, "SELECT * FROM tbl_user_permohonan");
                  while($row = mysqli_fetch_array($db)){
                      $potong = $row['file'];
                      $fix_potong = substr($potong,22);
                ?>

                  <tr>
                    <td><?php echo $no++ ?></td>
                    <td><?php echo $row['unit_cabang']; ?> </td>
                    <td><?php echo $fix_potong ; ?>        </td>
                    <td><?php echo $row['tanggal']; ?>     </td>
               <th>

               <!-- button download file -->
<a  href="download.php?filename=<?=$row['file'] ?>" type="button" class="btn btn-primary" >
<i class="fas fa-fw fa-edit"></i> Download</a></th>
                  </tr>

===============================================================================

<?php

include "../koneksi.php";

    if (isset($_GET['filename'])) {

    $filename    = $_GET['filename'];

    $file 		 = "../laporan-permohonan/".$_GET['filename'];

        if (file_exists($file)) {
            header('Content-Description: File Transfer');
            header('Content-Type: application/octet-stream');
            header('Content-Disposition: attachment; filename='.basename($file));
            header('Content-Transfer-Encoding: binary');
            header('Expires: 0');
            header('Cache-Control: private');
            header('Pragma: private');
            header('Content-Length: ' . filesize($file));
            ob_clean();
            flush();
            readfile($file);

            exit;
        } else {
            // $_SESSION['pesan'] = "Oops! File - $filename - not found ...";
            // header("location:laporanBulanan.php");

           echo "eroor";
        }
    }
?>