Add order by custom field for Smart Listing widget

order-by-custom-field.php

<?php

add_filter( 'jet-blog/smart-listing/query-args', 'my_listing_query_args' );

function my_listing_query_args( $args ) {
	
	$args['meta_key']  = 'your_key'; // Set meta key to sort by
	$args['orderby']   = 'meta_value';
	$args['order']     = 'DESC';
	$args['meta_type'] = 'DATE';
	
	return $args;
}