Here is the accordion.php code that creates the faq entries.

accordion.php.txt

I added the code from the documentation to my function.php in the child theme, but of course this is not a post type I'm dealing with, but a page with an add-on.

/**
 * This snippet adds metadata of "employee" post to search index
 */ 
add_filter('wpfts_index_post', function($index, $post)
{ 
    global $wpdb;

    // Basic tokens 
    /* 
     * This piece of code was commented out intentionally to display things
     * which was already done before in the caller code
    $index['post_title'] = $post->post_title;
    $index['post_content'] = strip_tags($post->post_content);
    */
    if ($post->post_type == 'employee') {
        // Adding new token "employee_data" specially for posts of type "employee"
        $data = array(); 
        $data[] = get_post_meta($post->ID, 'address', true);
        $data[] = get_post_meta($post->ID, 'phone', true); 
        $data[] = get_post_meta($post->ID, 'name', true);
        $data[] = get_post_meta($post->ID, 'function', true);
        $index['employee_data'] = implode(' ', $data);
    } 
    return $index; 
}, 3, 2);