How to fix error 403 when csrf enabled with ajax

Hi everyone, I'm struggling to retrieve data with ajax, I enabled csrf. When I use method: 'get' I get the data, but when I use post method did not work.

PHP Code:

//my route
$routes->post('view-category', 'Admin\Category::show_category');

//my controller
public function __construct(){
      helper('security');
}

public function show_category(){
      $output['csrf_token'] = csrf_token();
      $output['csrf_hash']   = csrf_hash();
      echo json_encode($output);
} 


Code:

// javascript
function view_category(){
      let url = 'view-category';
      let csrfName = '<?= csrf_token()?>';
    let csrfHash = '<?= csrf_hash() ?>';
      $.ajax({
           url: url,
           method: 'post',
           data: {csrfName: csrfHash },
           dataType: 'json',
           success: function(data)
           {
          alert("success");
           }
      })
}