Each time you request a new version, it will be uploaded in the Testflight section,
follow these steps to launch a new version.
1.- Enter https://appstoreconnect.apple.com/
2.- Click on My Apps
3.- Select the app to enter to its menu
4.- Click on Testflight
5.- Click on the version that you wish to send for testing
6.- Click on Provide information about the laws of exportation compliance
7.- Select Yes, and press Next
8.- Select Yes and click on Start inner tests
9.- Select the App Store option, and in the Compilation section, you will find the
version that you have chosen.
10.- Click on Save, and then click on Send for its review.