How to add a "Space" item at the toolbar with SwiftUI for macOS?

How to add a "Space" item at the toolbar with SwiftUI for macOS?

struct EditorView: View {
   
  @ToolbarContentBuilder
  func toolBarContent() -> some CustomizableToolbarContent {
    ToolbarItem(id: "toggle", placement: .navigation) {
      Button {
        NSApp.keyWindow?
          .contentViewController?
          .tryToPerform(#selector(NSSplitViewController.toggleSidebar(_:)),
                 with: nil)
      } label: {
        Label("Toggle Libary", systemImage: "sidebar.left")
          .accessibilityLabel("Toggle Libary")
          .help("Toggle Libary")
      }
    }
     
    ToolbarItem(id: "sfsymbols", placement: .automatic) {
      Button {
        print("")
      } label: {
        Label("SF Symbols", systemImage: "star.square.on.square.fill")
          .accessibilityLabel("SF Symbols")
          .help("SF Symbols")
      }
    }
    .defaultCustomization(.hidden)
     
     
     
    ToolbarItem(id: "flexibleSpace", placement: .automatic) {
      Spacer()
    }
    .defaultCustomization(.hidden)
     
    ToolbarItem(id: "save", placement: .automatic) {
      Button {
        print("")
      } label: {
        Label("Save", systemImage: "square.and.arrow.down")
          .accessibilityLabel("Save")
          .help("Save")
      }
    }
     
  }
   
  var body: some View {
    ZStack {
      CanvasView()
    }
    .toolbar(id: "main") {
      toolBarContent()
    }
  }
}

I use CustomizableToolbarContent like above code.

Spacer() will get a "FlexibleSpace" item of the toolbar.

ToolbarItem(id: "flexibleSpace", placement: .automatic) {
      Spacer()
    }

How can I get a "Space" item?

Thanks!