Other online stores advertise with the use of discount codes during check-out, which trigger a free giveaway. In practice, we would like to be able to send our customers a discount code that they must enter at the check-out, which then automatically adds an item to the basket for DKK 0. This discount code must be conditional on certain order amounts, which we can also make today, but must also be able to work on all orders without conditions on specific order amount. I agree that you can send a discount code to people where they can put the item in the basket and then they get a discount on this product with the discount code, but this solution makes it easier for our visitors/ our customers and feels more like something free that they don't have to “work” to get.

You can see an example from another webshop here that uses it extensively: https://billigvoks.dk/gratis-gave/