Why did my navigation bar and back buttons disappear when I added firebase auth?

I do not want a user to have to sign in to view basic app content. I want the app to open with my spash screen, navigate to home, and then allow a user to click to login if they want to make a story. I had the navigation set up perfect for the pages, but when I added firebase auth, all the navigation dissappeared and I cannot figure out how to get them back? What is going on with this?