Unfortunately, it is Apple’s official position that you need a Mac to publish apps to the iOS platform, and GameSalad complies with those licensing requirements.
You will need both a Macintosh computer and an Apple Developer license to publish to the iOS App Store. If you do not wish to purchase a Mac, one option is to utilize a cloud service such as MacInCloud.
You can, however, easily test your project with the GameSalad Viewer on any iOS device!