Parameter Encoding in Moya

My project is in Objective-C and I'm converting it to Swift. Objective-C project uses AFNetworking for networking. In new swift project I'm using Moya.

I have created Moya target named PhTrackerAPI,

public enum PhTrackerAPI {
    case login
    case checkNumberExist(phoneno: String, code: String)
    case todos
}

extension PhTrackerAPI: TargetType {
  public var baseURL: URL {
    return URL(string: "http://numberfinding.com/vaghani/call2loc/Api_c2l")!
  }

  public var path: String {
    switch self {
    case .login: return "/login"
    case .checkNumberExist: return "/check_number_exist"
    case .todos: return "/todos"
    }
  }

  public var method: Moya.Method {
    switch self {
    case .login, .checkNumberExist:
        return .post
    case .todos:
        return .get
    }
  }

  public var sampleData: Data {
    return Data()
  }

    var parameters: [String: Any]? {
        switch self {
        case .login:
            return [:]

        case .checkNumberExist(let phoneno, let code):
            return ["phone":phoneno,
                    "country_code":code]

        case .todos:
            return nil

        }
    }

  public var task: Task {
    switch self {
    case .login, .checkNumberExist:
        return .requestParameters(parameters: parameters!, encoding: JSONEncoding.default)
    default: return .requestPlain
    }
  }

  public var headers: [String: String]? {
    return ["Content-Type": "application/json"]
  }

  // 7
  public var validationType: ValidationType {
    return .successCodes
  }
}

When I request API from Postman, it is giving response, But If I call it via Moya, it gives error of "Parameter not found". Why this error occurs? Anyone can help me?

EDIT:

My API wants parameters in form data. So I have updated task as below and it is works fine now.

 var task: Task {
    switch self {
    case .checkNumberExist:
         var multipartData = [MultipartFormData]()
               for (key, value) in parameters! {
                   let formData = MultipartFormData(provider: .data("\(value)".data(using: .utf8)!), name: key)
                   multipartData.append(formData)
               }
               return .uploadMultipart(multipartData)
    default: return .requestPlain
    }
 }