How to set a webform default value for anonymous user?

I have been using hook form alter for a webform, to set a default value for a webform added as a block to a page. Below is the code, the code only works for users who have logged, but for anonymous or non logged in user the field is not working with a default value even with else condition or with anonymous check. what is wrong in the code below?

function mytheme_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id)
{
$current_role = \Drupal::currentUser()->getRoles();
if ($form_id == 'webform_submission_add_form'){
  if (in_array("user1", $current_role)) {
     $form['elements']['user']['#default_value'] = 'logged';
    }
  else{
     $form['elements']['user']['#default_value'] = 'not logged';
    }
  if (\Drupal::currentUser()->isAnonymous()) {
     $form['elements']['user']['#default_value'] = 'not logged';
     }
  if (in_array("anonymous", $roles)) {
     $form['elements']['user']['#default_value'] = 
     'not logged';
     }
   }
}

Webform has the built-in ability to define default values for form fields when they're empty. If I remember correctly, it's in the Advanced section when you configure a field. The default value accepts either a static value or a token. Create a custom token if you want to programmatically generate the default value, then configure the webform field to use that token as the default value.

I recommend doing it this way to not hardcode that logic to a specific form, i.e. you can reuse that token in another form. You can also remove it easily from admin without going into code, should you not want it anymore.