There are two threads on this subject.
https://nodakangler.com/forums/threads/onx-fish.19300/#post-458576
If you have a ND Game and Fish website account to buy licenses or get your HIP number etc., there should be a message in your inbox to get ONX Fish free for three months, but when I opened the link and registered, it gave me an expiration date of 12-31-25. Messed around with it a little, and just from first appearances, the ND Game and Fish Fishing Atlas and ONX Fish are not the same maps.
https://geocortex.gf.nd.gov/Html5Viewer/?viewer=Fish has way better maps. Here is just one example.
ONX Fish
ND Game and Fish Fishing Atlas Map
Seeing that little guy and being able to hit Follow Me and drive right on top of it has helped me catch fish. Can't see that detail on ONX Fish.
Another example of bad information is ONX Fish saying a lake about an hour north is a trophy bluegill lake because a 10 inch bluegill was caught in a test net, but when you look at game and fish information, that was seven years ago, and a bluegill hasn't been netted or shocked in that lake since.