Identify the error in this SwiftUI code that tries to present a full screen cover:

Identify the error in this SwiftUI code that tries to present a full screen cover:

struct ContentView: View {
  @State var showFullScreen = false
  var body: some View {
    Button("Open") {
      showFullScreen = true
    }
    .fullScreenCover(isPresented: showFullScreen) {
      Text("Full Screen")
    }
  }
}