added missing square brackets

templates/noonce.php

 <?php
+
 /**
  * @var \WPDesk\Forms\Field $field
  * @var string $name_prefix
  * @var string $value
  */
-?>
-<?php wp_nonce_field( $field->get_meta_value( 'action' ), $name_prefix . $field->get_name() );
+\wp_nonce_field($field->get_meta_value('action'), $name_prefix .'['. $field->get_name().']');