This partial in Twig defines "Confirm" one-click action for E-Mail messages.

confirm-one-click-action.twig

{#
    Defined "Confirm" one-click action.

    @param {string} title
    @param {string} url
    @param {string} [description]
#}
<div itemscope itemtype="http://schema.org/EmailMessage">
    <div itemprop="potentialAction" itemscope itemtype="http://schema.org/ConfirmAction">
        <meta itemprop="name" content="{{ title }}"/>
        <div itemprop="handler" itemscope itemtype="http://schema.org/HttpActionHandler">
            <link itemprop="url" href="{{ url }}"/>
        </div>
    </div>
    {% if description %}
        <meta itemprop="description" content="{{ description }}"/>
    {% endif %}
</div>