Help getting my login button to redirect the user

I want to make it so that after a user signs in and gets a session, they get redirected to a previously protected page. Additionally i want the logout button to redirect the user to a unprotected landing page. However my current attempt is not working. My login form successfully gets a session created (I know this because when I navigate to the protected page I can see it) My Login form has a condition that if res.ok == true, then redirect("/guestbook"), but I don't know why that isn't working? Could someone take a look?