Writing twice to sqlite database and get error SQLSTATE[HY000]: General error: 5 database is locked

[ffuentese]

I wrote the following function to get input from the user

app()->post('/createThread', function () {
        
  $user = auth()->user()->get();
  if (!$user) {
      return response()->render('login',[
      'status' => 'error',
      'message' => 'Debe iniciar sesión',
      'data' => auth()->errors(),
    ]);
  }
 
$userData = request()->get(['title', 'message', 'topic_id']);
$db = db();
    $db->insert('threads')->params([
        'title' => $userData['title'],
        'user_id' => auth()->id(),
        'topic_id' => $userData['topic_id']
   ])->execute();
 
  $thread_id = $db->lastInsertId();
 
$db->insert('comments')->params([
        'message'=>$userData['message'],
        'user_id' => auth()->id(),
        'thread_id'=>$thread_id
 ])->execute();
 
  return response()->redirect('/thread/{$thread_id}');
 
});

However, I'm getting the aforementioned error 5 and I tried with the transaction function callback but I get another error "no active transaction". The documentation is not super exhaustive and no resource is helpful. Thanks.