在密码中授权 type basic 时，符号#swift 4 被错误传输到服务器

这是基本的标头代码：

let userName = "userName"
let userPassword = "{"pass":password}"
loginString = String(format: "%@:%@", userName, userPassword)
let loginData = loginString.data(using: String.Encoding.utf8)!
let base64LoginData = loginData.base64EncodedString()
let url = URL(string: "https://mysight.ru/authorize")!
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("Basic \(base64LoginData)", forHTTPHeaderField: "Authorization")
let configuration = URLSessionConfiguration.default
let session = URLSession(configuration: configuration)
let task = session.dataTask(with: request as URLRequest) { (data, response, error) in
            self.data = data
            self.response = response as? HTTPURLResponse
            self.error = error

            if (response as? HTTPURLResponse) != nil {
                let myHttpResponse = response as! HTTPURLResponse
                let statusCode = myHttpResponse.statusCode
                switch (statusCode) {
                    case 200:
                        print("Get UserTokens Processing StatusCode=200")
                    case 401:
                        print("User Unauthorized")
                    case 500:
                        print("Get UserTokens Processing StatusCode=500")

                    default:
                        print("Get UserTokens Processing StatusCode=Unknown")
                }
            }
            self.isFinished = true
        }
        task.resume()
    }

如果密码仅包含字母和数字 - 一切正常，状态 200，如果密码中的 # 符号 - 立即出现错误：状态 401：用户未授权

我知道问题出在#字符的传输中，但我不明白如何解决这个问题。如果有人遇到，请帮助。