Wenn Sie bereit sind das auf Englisch zu lesen :-)
If you can use a computer with iTunes 12.6.5 or older, or a device with the required minimum iOS version, you can download the new version to them. Now go to your old device and a cloud icon with a download icon should appear next to the app. Try downloading it. It will offer an older version if one is available. If this is an app that uses a service (e.g., a streaming media provider) there is no guarantee the old version will actually work with the service but I have found many old versions are available and provide partial functionality.
Downloading Older iOS 9.3.5 Versions of A… - Apple Community -
https://discussions.apple.com/docs/DOC-13282