Add shortcode in cf7 with plugin Listo

function.php

<?php
add_filter('listo_list_types', 'listo_list_types_func');
function listo_list_types_func($list_types){
	$list_types['physicians'] = 'Listo_Physicians';
	return $list_types;
}

class Listo_Physicians implements Listo {

	public static function items(){
        $args = array(
            'post_type' =>  'physicians',
            'post_status'   =>  'publish',
            'posts_per_page'    =>  -1,
        );
        $query = new WP_Query($args);
        $userData = array();
        $items[] = "Physicians";
        foreach($query->posts as $item)
        {
            $items[$item->ID] = $item->post_title;
        }
        return $items;
    }

    public static function groups(){}
}