1. Click on the "Build App" button
  2. In the following dialog, first select whether you wish to build a preview app (2.1) or create a release app 
    Note: If you build a preview app, you only need to specify the platforms for which it is intended to be built (2.2). This selection also depends on the settings in the basic settings under "Select your target platforms for your app."

    Note : The earlier versions of the app are overwritten.

  3. Finally, click on "Build" to begin building the new app version. It lasts a few minutes. Afterwards, you can install the new version on your mobile devices.