Codeigniter url in Cyrillic like ������ how to fix it?

Question

CodeIgniter

There is a project on codeigniter, there is a piece of code that pulls the name of the object from the base and generates a link, but if the name is in Cyrillic, it displays ����� .

Help fix it.
I bring a piece of code.

function get_listing_url($listing_id = ""){
    $CI =&  get_instance();
    $CI->load->database();
    $listing = $CI->db->get_where('listing', array('id' => $listing_id))->row_array();
    $custom_url = site_url($listing['listing_type'].'/'.slugify($listing['name']).'/'.$listing_id);
    return $custom_url;