It depends on what form of two-factor authentication your card issuer (bank) uses, however SMS + code is most commonly used in Denmark if you want to avoid using your MitID .
You can therefore avoid using MitID , if you use method 2 when paying online. Here you receive a one-time code via SMS, which you need to complete the purchase, and you must enter a password that you choose yourself.
If you have not used this method before, you need to use your MitID the first time you use it. If you need to register, you can do so here: https://enroll.3dsecure.no/nets-MitID -enroller/EnrollSite
It is also possible to purchase without MitID , if you use MobilePay, Google Pay or Apple Pay.