I have no idea why, but on XCode, to access the Archive button in Product, I change my device to a generic IOS device. Whenever I do that and press the Archive button, I get this message: "No code signing identities found: No valid signing identities (i.e. certificate and private key pair) were found." I have no idea how to fix this and I've searched. Any help is appreciated. Thanks.
In order to submit your app to AppStore, you need to sign your app with Distribution certificate and valid provision profile.
You can have a look at this example