swift OAuth2 OAuthSwifter错误-10

我需要使用Fitbit api，但我无法获得令牌。我收到的错误是操作无法完成。（OAuthSwiftError错误-10。）

我的代码：

let oauthswift = OAuth2Swift(
    consumerKey:    "228Q6N",
    consumerSecret: "de8dc5301fbfb8ada6d0d327fb8395c2",
    authorizeUrl:   "https://www.fitbit.com/oauth2/authorize",
    accessTokenUrl:  "https://api.fitbit.com/oauth2/token",
    responseType:   "token"
)
let handle = oauthswift.authorize(
    withCallbackURL: URL(string: "DemoSmartHeath://oauth-callback/fitbit")!,
    scope: "sleep+settings+nutrition+activity+social+heartrate+profile+weight+location", state:"fitbit",
    success: { credential, response, parameters in
        print("credential : \(credential)")
        print("response : \(response)")
        print("parameters : \(parameters)")
    },
    failure: { error in
        print(error.localizedDescription)
    }
)

AppDelegate：

func application(_ application: UIApplication, open url: URL, sourceApplication: String?, annotation: Any) -> Bool {
    if (url.host == "oauth-callback") {
        OAuthSwift.handle(url: url)
    }
    return true
}

有人能帮我吗