我正在创建一个flutter应用程序来在列表中显示用户。我可以获取和打印数据，但是由于出现此错误异常，我无法显示数据。_TypeError（键入'List

我使用dio包来取数据。这里是用于进行api调用的代码

class DioClient {
  final Dio _dio = Dio();

  final _farmerUrl = 'https://retoolapi.dev/Rzl99e/farmers';

  Future<Users?> getUser() async {
    Users? users;
    try {
      Response userData = await _dio.get(_farmerUrl);
      print('User Info: ${userData.data}');
      users = Users.fromJson(userData.data);
    } on DioError catch (e) {
      if (e.response != null) {
        print('Dio error!');
      } else {
        print('Error sending request! '+ e.message);
      }
    }
    return users;
  }  
}

这是我用来解析json响应的模型类

List<Users> usersFromJson(String str) => List<Users>.from(json.decode(str).map((x) => Users.fromJson(x)));

String usersToJson(List<Users> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

class Users {
    Users({
        this.id,
        this.bio,
        this.email,
        this.lastName,
        this.firstName,
        this.phoneNumber,
        this.memberNumber,
    });

    int? id;
    String? bio;
    String? email;
    String? lastName;
    String? firstName;
    String? phoneNumber;
    String? memberNumber;

    factory Users.fromJson(Map<String, dynamic> json) => Users(
        id: json["id"],
        bio: json["bio"],
        email: json["email"],
        lastName: json["last_name"],
        firstName: json["first_name"],
        phoneNumber: json["phone_number"],
        memberNumber: json["member_number"],
    );

    Map<String, dynamic> toJson() => {
        "id": id,
        "bio": bio,
        "email": email,
        "last_name": lastName,
        "first_name": firstName,
        "phone_number": phoneNumber,
        "member_number": memberNumber,
    };
}

这是我用来显示用户列表的代码

      body: SingleChildScrollView(
        child: Center(
          child: FutureBuilder<Users?>(
            future: _client.getUser(),
            builder: (context, snapshot) {
              if (snapshot.hasData) {
                Users? userInfo = snapshot.data;
                if (userInfo != null) {
                  return ListTile(
                    title: Text(userInfo.firstName! + ' ' + userInfo.lastName!),
                    subtitle: Text(userInfo.phoneNumber!),
                  );
                }
              }
              return CircularProgressIndicator();
            },
          ),
        ),
      ),

我可以更改什么以完全显示用户列表。