Thank you! This code i must add to file functions.php ?
`// Replaces ‘ru’ by ‘ru-UA’ on all pages.
add_filter( ‘pll_rel_hreflang_attributes’, function( $hreflangs ) {
$hreflangs[‘ru-UA’] = $hreflangs[‘ru’];
unset( $hreflangs[‘ru’] );
return $hreflangs;
} );