title: Custom parameters when API calling with Swift 5
body: <p>I've got this function to fetch a JSON API, but I need to set custom parameters.</p>
  
  <p>Here is the function:</p>
  
  <pre><code>func fetchTipsJson(completion: @escaping (Result&lt;Root, Error&gt;) -&gt; ()) {
          let urlString = "http://telemedapi_dev.assistcard.com/Api/Config/GetConfigGroupList"
          guard let url = URL(string: urlString) else { return }
  
          URLSession.shared.dataTask(with: url) { (data, resp, err) in
              // Error
              if let err = err {
                  completion(.failure(err))
                  return
              }
  
              // Successful
              do {
                  let tips = try JSONDecoder().decode(Root.self, from: data!)
                  completion(.success(tips))
  
                  print(tips)
              } catch let jsonError {
                  completion(.failure(jsonError))
              }
          }.resume()
      }
  </code></pre>
  
  <p>And here are the parameters:</p>
  
  <pre><code>{
      "Parameters": {
          "CountryCode": 540,
          "ConfigurationPath": "TelemedGlobalConfig&gt;Tips",
          "LogApiCallsStatus": 2
      },
      "VisitorIp": null,
      "ApplicationName": null,
      "CurrentUICulture": "es-ES"
  }
  </code></pre>
  
  <p>How can I do this? I can't find anything. Notice that I'm using the new <code>Result</code> from Swift 5, don't know if that changes anything.</p>