If your car is registered abroad, you must pay to register it in Denmark if you want to be able to use your car legally in the country.
If you have a permanent address in Denmark, your car must have Danish license plates. You will also have to pay a registration fee no later than 14 days after your arrival in Denmark.
If you do not have a permanent address in Denmark, for example if you are a student in the country or working in Denmark for a limited time, you should apply for a special permit to drive a car that is registered abroad.