@Laura5961 message or call Airbnb. If you get a good agent they will request the correct dept. to put you in the cabins category. Usually takes a week or two.
To improve your chances of being included in the cabin category, you can make sure your list of amenities and features is complete and current, and key features of your space are clearly depicted with high-quality photography.
By making sure you have selected all the amenities you have to offer, you have a better chance of showing up in the relevant category. You may find more information here: How Airbnb Categories Work.