Laravel Defender（垃圾邮件防护）使用OLD并显示错误

I'm using https://github.com/thomastkim/laravel-spam-prevention but I want to display validator messages and old content back to user but Idk if it's possible if names are randomized. What I'm currently doing: Example of input:

<div class="form-group{{ $errors->has(Defender::get('firstname')) ? ' has-error' : ''}}">
      <label for="{{ Defender::get('firstname') }}" class="control-label">First name:</label>
      <input type="text" name="{{ Defender::get('firstname') }}" value="{{old(Defender::get('firstname'))}}" class="form-control" id="{{ Defender::get('firstname') }}">
      <span class="text-danger"> {{ $errors->first(Defender::get('firstname'))}} </span>
    </div>

and in my request there is rule:

Defender::get('firstname') => 'required',

and there is message:

 Defender::get('firstname').'.required' => 'You must enter your first name',

But obviously when form gets submited {{ $errors->first(Defender::get('firstname'))}} this won't be same as before... So any idea what I should do here in order to display messages to user and get old input ?