Order with custom table

I'm not able to order a view using a custom table field (data_ora_inizio).
This is the code, any ideas?

{% set args = { post_type: 'evento', posts_per_page:10, orderby: 'data_ora_inizio', order: 'DESC'} %}
{% set posts = mb.get_posts( args ) %}
<main class="max-x-3xl mx-auto p-4">
    {% for post in posts %}
        <div class="flex mb-6 border border-gray-400 rounded">
            <div class="flex-1 p-4">
                <h3><a href="{{ post.url }}"> {{ post.title }}</a></h3>
                <em>{{ post.ID }} --- {{ post.data_ora_inizio | date( 'd/m/Y' ) }} - {{ post.citta.label }}</em>
                <div class = "mt-3">
					{{ post.indirizzo }}<br><br>
                </div>
            </div>
        </div>
    {% endfor %}
    
    {{ mb.get_the_posts_pagination() }}
</main>