How to create a ZIP file using PHP and delete it after user

$zip = new ZipArchive();
$filename = "files.zip";

if ($zip->open($filename, ZipArchive::CREATE) === TRUE) {
  $zip->addFile("file1.txt");
  $zip->addFile("file2.txt");
  $zip->addFile("file3.txt");
  $zip->close();
  // Download the ZIP file
  header('Content-Type: application/zip');
  header('Content-disposition: attachment; filename=' . $filename);
  header('Content-Length: ' . filesize($filename));
  readfile($filename);
  // Delete the ZIP file
  unlink($filename);
} else {
  echo "Failed to create ZIP file";
}