By default, iOS Apps can only make HTTPS requests. If you're running a backend locally, perhaps one of our samples, it might make sense to disable this behavior.
In your App's Info.pist file, in Xcode, add the following fields:
If your backend is not running locally, replace localhost with its IP address or domain.
Note: You should only do this for test/development purposes. In production, it's highly recommended that you use an HTTPS service.