Perform the following steps to submit your app to the App Store:
After the successful completion of Archive build, click Submit To App Store on the screen displayed in XCode.
Your app is submitted successfully, if you do not encounter any issues.
If you encounter any issues using this approach, upload your Archive (.ipa) file manually by performing the following steps:
Open the Application Loader utility using the Open Developer Tool Menu item from XCode.
In the Application Loader utility, click on Export and select Save for iOS App Store Deployment.
Choose your Developer account and click OK.
Once the .ipa file is created for your App, you can then use iTunes Connect to upload the App to the App Store.