Building .csv downloader

I am implementing the functionality for an admin to generate .csv files with all the data from the table Events in a certain period of time.

The problem is I’m still getting these errors:

Warning (2): rawurlencode() expects parameter 1 to be string, array given [CORE\src\Routing\Route\Route.php, line 574] Warning (2): rawurlencode() expects parameter 1 to be string, array given [CORE\src\Routing\Route\Route.php, line 574]

I am suspecting that this is the problem with my redirect line.

exportcsv method in EventsController

 public function exportcsv($beginning = null, $end = null)
{
 if ($this->request->is('post')) {
  $beginning = $this->request->data['Export']['beginning'];  
  $end = $this->request->data['Export']['end'];              

  return $this->redirect([$beginning, $end]);       //I think that this line causes trouble
 }

 if (!$beginning && !$end) {
  return $this->render();
 }

 /* existing export action code *\
}

exportcsv.ctp view:

<div class="events form large-6 medium-4 columns content">
  <?= $this->Form->create('Export'); ?>
  <?= $this->Form->input('beginning', array('type'=>'datetime', 'interval' => 15, 'label' => 'Beginning:')); ?>
  <?= $this->Form->input('end', array('type'=>'datetime',  'interval' => 15, 'label' => 'End:')); ?>
  <?= $this->Form->button(__('Add')) ?>
  <?= $this->Form->end() ?>
</div>

I am new to CakePHP and I think that there is some minor error in my code that causes it. Can you help me fix the problem?

I solved the problem with a simple transform both arrays into a string values.