couldn't create named routes in Flutter - flutter

Question

I defined needed routes in Material App and everything works fine, bit I have to add another button which should lead to authorisation page and now I am getting this error:
The following assertion was thrown while handling a gesture:
Could not find a generator for route RouteSettings("/changeUsers", null) in the _WidgetsAppState.
Make sure your root app widget has provided a way to generate
this route.
Generators for routes are searched for in the following order:
1. For the "/" route, the "home" property, if non-null, is used.
2. Otherwise, the "routes" table is used, if it has an entry for the route.
3. Otherwise, onGenerateRoute is called. It should return a non-null value for any valid route not handled by "home" and "routes".
4. Finally if all else fails onUnknownRoute is called.
My code look like this:
return MaterialApp(
debugShowCheckedModeBanner: false,
initialRoute: '/',
routes: {
'/': (context) => const AuthorizationPage(),
'/adminLogin': (context) => const AuthInsertLogging(),
'/mainPageUsers': (context) => const TabBarBottomUsers(),
'/mainPageAdmin': (context) => const TabBarBottom(),
"/logout": (_) => new AuthorizationPage(),
'/changeUsers': (_) => AuthorizationPage(),
},
);
}
This is the button I tried to make route:
child: ElevatedButton(
onPressed: () {
Navigator.pushNamed(context, '/changeUsers');
},
child: Text(
'Change User',
style: GoogleFonts.montserrat(
color: Colors.white,
fontSize: 20,
fontWeight: FontWeight.w500,
letterSpacing: 2),
),

Answer 1

This is because you use the AuthorizationPage for '/' home, '/logout' and '/changeUsers' routes. There is a rule for routes property in Flutter documentation. See details here
If home is specified, then it implies an entry in this table for the
Navigator.defaultRouteName route ( here '/' ), and it is an error to
redundantly provide such a route in the routes table.
The rule says there must be only one home route ( here '/' route ) is specified. Here there are three routes pointing to same page.
So, just remove '/logout' and '/changeUers' routes and write onPressed function as follows.
Navigator.pushNamed(context, '/');