Can’t login to App – National Park Trail Guide Review

It always comes up with an unknown error when I attempt to login to the app. It isn’t a username/password error nor does it give me an error code of any kind. I can login via the browser so I know my username and password are fine. I also removed and readded the app. Nothing works. I really wanted the app so I can plan our adventure. Please fix.
Review by Haliebyrd on National Park Trail Guide.