If you wonder where the file sharing for your macOS server has gone in iOS 12, we have an answer for you: to nirvana.
While it was still possible under iOS 11 to simply add the macOS server as source in the app “Files”, this possibility is no longer available. But this should have been noticed only by users whose macOS server is still based on versions that are designed for macOS 10.11 or 10.12. Starting with High Sierra (10.13) and the corresponding server version 5.4, Apple had already deleted the option from the server – no matter if there was still iOS 11 available.
Now the connection was also cut vice versa: from new iOS to old macOS server. Apple has already warned some time ago that many services are simply cancelled. If this concerns you, you have to go to the listed alternatives.
