CakeContactUs/templates/element/ContactUsFormSubmissions/form.php

<?php
/**
 * @var \App\View\AppView $this
 * @var \Cake\Datasource\EntityInterface $contactUsFormSubmission
 */

$fields = \Cake\Core\Configure::readOrFail('ContactUs.fields');
?>
<?php
echo $this->Form->control('name');
echo isset($fields['email']) && $fields['email'] ? $this->Form->control('email', ['required' => true]) : '';
echo isset($fields['subject']) && $fields['subject'] ? $this->Form->control('subject', ['required' => true]) : '';
echo $this->Form->control('message');
echo isset($fields['captcha']) && $fields['captcha'] ? $this->Captcha->render(['placeholder' => __('Please solve the riddle')]) : '';

?>