Picker with Fetchrequest (SwiftUI)

Hello, I have some trouble with pickers with Fetchrequest. I can display a list but can't manage the picker.

struct DepenseView: View {
    
    @Environment(\.managedObjectContext) var moc
    @FetchRequest(sortDescriptors: []) var TypeDepenses: FetchedResults<TypeDepense>
    @State var selectedDepense : String = "Autre"
       
    var body: some View {
        
        Text("Nouvelle dépense")
                .font(.title)
                .fontWeight(.bold)
                .padding(.top)
        List {
                ForEach(TypeDepenses) { typb in
                    Text(typb.type ?? "Unknown Title")
                }
        }
            
        List {
            Picker("Type", selection: $selectedDepense){
                ForEach(TypeDepenses){ type in
                    Text(type.type ?? "Unknown Title")
                    Text("Autre").tag("Autre")
                }
            }
        }
    }
}