Apple recently announced on the developer website that the App Store now supports downloading hidden apps only through links. For some apps that are not suitable for public distribution, developers can submit requests on the website to distribute hidden apps. These apps do not appear in any App Store categories, recommendations, charts, search results, or other listings, and are also accessible through Business Manager and Campus Manager.
Apple says apps that sell tools and resources for specific organizations, special events, research, or employees are good candidates for hidden distribution. This feature is supported in all countries where the App Store is available
Developers can submit application forms for apps. If approved, the App’s distribution method will be changed to Unlisted App and will apply to all future versions of the App. Users can download the App through the direct chain, and the direct chain will remain unchanged.
According to Apple, Unlisted apps must be ready for final distribution, and requests for apps in beta or pre-release status will be rejected. In other words, Unlisted App cannot be tested using TestFlight, etc.