You can manage your domain's DNS through enavn.dk's client area. Once logged in, you can access the Domains -> Manage DNS menu. You will then see a list of domain names that you can edit.
Find the desired domain name in the overview and click on the Edit Zone button to the right of as illustrated below.
If you want to create a new DNS record, click Add Record in the upper right, which opens a new window for the purpose.
The Name field should be filled in with the subdomain that you want to create, for example "new" as in the example above. Then select the record Type you want to create. Based on your choice of type, the surrounding fields will change to fit the respective type of record.
NB: If you need your new DNS record to be created directly on the "root domain", you can enter an @ in the Name field, or your domain name without a subdomain such as "example.com".
The new DNS record will now be found in the overview.