Information in emails: only show klarna order id if it actually exists

Hello. The plugin has the option to display additional information in the emails.
We have an order confirmation. This seems to be sent in such a way that the Klarna order ID is not yet available. The Klarna order ID is available for later emails. It would be good if the one line with “klarna order id” would not be displayed if there is no id. It could also be useful if the hook can also be removed for individual emails. This could be done, for example, by marking the HTML callback as a public static function. Then we can work via remove_filter to remove the callback for individual mails.