fix

lib/models/login_resp.dart

@@ -0,0 +1,27 @@
+import 'package:json_annotation/json_annotation.dart';
+
+/// This allows the `User` class to access private members in
+/// the generated file. The value for this is *.g.dart, where
+/// the star denotes the source file name.
+part 'login_resp.g.dart';
+
+/// An annotation for the code generator to know that this class needs the
+/// JSON serialization logic to be generated.
+@JsonSerializable()
+class LoginResp {
+  LoginResp(this.token, this.msg);
+
+  String token;
+  String msg;
+
+  /// A necessary factory constructor for creating a new Configs instance
+  /// from a map. Pass the map to the generated `_$ConfigsFromJson()` constructor.
+  /// The constructor is named after the source class, in this case, Configs.
+  factory LoginResp.fromJson(Map<String, dynamic> json) =>
+      _$LoginRespFromJson(json);
+
+  /// `toJson` is the convention for a class to declare support for serialization
+  /// to JSON. The implementation simply calls the private, generated
+  /// helper method `_$LoginRespToJson`.
+  Map<String, dynamic> toJson() => _$LoginRespToJson(this);
+}