Could not find a generator for route RouteSettings("/page", null) in the _CupertinoTabViewState

Переходы по Bottom Navigator работают, но если я хочу перейти на страницу дальше, то выдает ошибку:

Could not find a generator for route RouteSettings("/page", null) in the _CupertinoTabViewState.

Generators for routes are searched for in the following order:

1. For the "/" route, the "builder" 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 "builder" and "routes".
4. Finally if all else fails onUnknownRoute is called. Unfortunately, onUnknownRoute was not set. When the exception was thrown, this was the stack

Я использую CupertinoTabBar, но в качестве корневого виджета я хочу оставить MaterialApp, поэтому в нем я использую onGenerateRoute. код залил на [dartpad]:(https://dartpad.dev/32171b62a2038ed176de33a9d4ad3a31)