Reading [Declare Properties](https://docs.mongodb.com/realm/sdk/ios/examples/define-a-realm-object-model/#declare-properties) I see there are three options:
- Swift using a post 10.10.0 version of the Realm SDK
- Objective C
- Swift pre 10.10.0
Suggestion: in the swift tab add a sentence: "This works with Realm Swift SDK version 10.10.0+" or something similar to make super-clear you need that version to make these new property-wrappers work and avoid confusion.