We do not require an additional payment after your order has been delivered to you.
If you placed your order using Klarna or Billink, they will ask you to fulfill your payment from their end.
In case you haven't used any after-pay services and still receive mail that requires an additional payment, be sure to check the sender information as it may not be from us and may be a phishing mail in which case we advise you to block and report said mail.