What is a "normal model". Models - Data Transfer Objects (DTO)s - usually just hold data. These are clients, not models. And we use struct because we dislike reference types.
You should probably look more into Swift-Dependencies. Some examples and documentation.
but you should probable import Dependencies and not DependencyMacros. Did you get asked by xcode to enabled macros? if so, did you enable? Else restart xcode.
Have a look at a simple client here sargon/examples/iOS/Backend/Sources/Planbok/Dependencies/PasteboardClient.swift at main · radixdlt/sargon · GitHub