From order item post meta

Hi
Very strange. This php code works –

$tele = wc_get_order_item_meta( $item['item_id'], 'Телефон', true );}

And this one doesn’t work –

$strah1 = wc_get_order_item_meta( $item['item_id'], '1-й ФИО русскими буквами', true );

The problem with the Cyrillic alphabet. Latin field names – no problem. How to avoid this error?