How can a nested ObservableObject reference the parent EnvironmentObject - SwiftUI

Question

How can a nested ObservableObject reference the parent

Fatal error: No ObservableObject of type Model found. A View.environmentObject(_:) for Model may be missing as an ancestor of this view.

class Model: ObservableObject {
    
    @Published var subModel = SubModel()
    @Published var email: String = ""
}

class SubModel: ObservableObject {
    
    @EnvironmentObject var model: Model // This EnvironmentObject doesn't work. See error.
    
    func run() {
        model.email = "new@test.com" // How can I update the email here? Throws error..
        // Fatal error: No ObservableObject of type Model found. A View.environmentObject(_:) for Model may be missing as an ancestor of this view.
    }
}

struct MainView: View {
    
    @EnvironmentObject var model: Model // This EnvironmentObject works great
    
    var body: some View {
        Button(action: {
            model.subModel.run()
        }) {
            Text("Click me")
        }
    }
}