[已解决] I have a code that being translated and found in String Translation but it's not been translated in place

I have a code that being translated and found in String Translation but it's not been translated in place

add_filter( 'woocommerce_email_subject_customer_processing_order', 'change_processing_mail_subject', 10, 2 );
function change_processing_mail_subject( $subject, $order ) {
global $woocommerce;
$items = $order->get_items();
foreach ( $items as $item ) {
$product_name = $item->get_name();
}
$subject = __('Your registration for the course ').$product_name;
return $subject;
}