1. In your plist, increase the version number, labeled “Bundle version string (short)”.
2. Submit an archive of your app and upload it to App Store Connect. Make sure you have checked “Manage Version and Build Number.”
3. On App Store Connect, go to your app and hit the blue plus button next to your app name. Add the version number.
4. Make any changes you want to the description/other info. Fill out the section “What’s New in This Version”.
5. Scroll down to the section “Build” and select the build you uploaded.
6. Click “Save”, then “Add for Review” and “Submit for App Review”.