data type on excel

app/Http/Controllers/MainController.php

     {
         $vips = RSVP::where('is_vip', true)->get();
 
-        $csvData = "Nama,Bilangan,No Tel\n";
+        $csvData = "\xEF\xBB\xBF" . "Nama,Bilangan,No Tel\n";
         foreach ($vips as $vip) {
             $csvData .= "{$vip->name},{$vip->member},{$vip->phone}\n";
         }

resources/views/attendance.blade.php

                 @endforeach
                 </tbody>
             </table>
-            <a href="{{ route('download.vip.csv') }}" class="btn btn-primary">Download VIP Data</a>
+            <a href="{{ route('download.vip.csv') }}" class="btn">Download VIP Data</a>
         </div>
         
         <div>