Resolved: Flutter – Pass data to multiple stateful pages

     Navigator.push(
             context,
             MaterialPageRoute(
                 builder: (context) =>
                     TodayPage(lg_username: unameController.text)),).then((value) => _login(lg_username));

class StaticVariable {
  static UserModel? user;
  static String? userId;
}

ElevatedButton(
        child: const Text('Navigator'),
        onPressed: () {
          StaticVariable.userId = 'YOUR USER ID';
          Navigator.push(
            context,
            MaterialPageRoute(
                builder: (context) =>
                    TodayPage(lg_username: unameController.text)),);
        },
      )

Text(StaticVariable.userId ?? '')