App Store applications are managed through the App Store Connect website (at appstoreconnect.apple.com/). Log in using your Apple developer account and create a new application (if you have not already done so). This is where you add the metadata that will be displayed in the store—be sure to check the information carefully as some data cannot be changed after release. Well-chosen descriptions and screenshots will help your application to be more easily discovered. Within this app definition, you need to start preparing a new release, with an appropriate version number and supporting information. You will probably notice that you are not yet able to select a build—to enable this, we first need to upload the compiled package.

The application loader tool is the easiest way to upload a new build: open the app and log in with your Apple ID. Once logged in, you will be asked to choose the application to upload; select the matching application and progress to the upload. Once complete, the build will appear in the App Store Connect website (you may need to refresh the page). If you prefer command-line tools for managing the progress, you can use xcrun altool, which provides the same capability. Once you've chosen this new build, you can press the Submit for Review button to start the review process.