Cara mengkonfigurasi bahasa permintaan WP_Query wpml

Mengapa opsi “lang” tidak berfungsi terkunci WP_Query ?

 $args = array(
    "post_type"      => $_POST["art"],
    "post_status"    => "publish",
    "order"          => "DESC",
    "orderby"        => "date",
    "lang"           => $_POST["art_lang"],
    'search_prod_title' => $_POST["term"],
    "posts_per_page" => -1
);