1. of July 2021 new customs registrations are required by law.
Basically, it is a registry of all shipments abroad. In daily terms, it is referred to as IOSS.
You will need to hand in reports of your shipments.
In Webshipper you will not need to do much. If you get a VAT number you can also add it to your sender address in the Location setting. Learn more here.
Read more about it here: https://skat.dk/
Contact Skat.dk for further assistance.