Тодор

$order = $modx->getObject('msOrder', ORDER_ID);
$address = $order->getOne('Address');

$address->set('city', "New York");
$address->set('street', "st.Metrofana 15");

$properties = array(
    'test' => htmlentities('My test properties field', ENT_COMPAT | ENT_HTML401,'UTF-8'),
    'test 2' => htmlentities('My test properties field2', ENT_COMPAT | ENT_HTML401,'UTF-8'),
);

$address->set('properties', json_encode($properties));
$address->save();

{'!mySnippet' | snippet}
{if $_modx->getPlaceholder('my_pls')}
    Мой плейсхолдер равен {$_modx->getPlaceholder('my_pls')}
{/if}

<?php
$modx->setPlaceholder('my_pls', 1);

<input name="note" type="hidden" value=""/>

$resource->save();

<!--tickets_captcha
<div class="form-group">
    <label for="comment-captcha" id="comment-captcha">[[+captcha]]</label>
    <input type="text" name="captcha" value="" id="comment-captcha" class="form-control" />
</div>
-->

[[#GET.tags]]

{$.get['tags']}