I cant see my widget (native c++)

I want to make widget without bindwidget.

I can check with debugging that all the member variables and widgets are created. However, it does not appear on the design screen and does not add to the screen even if I use the add view port.
I want to know the reason for this.

	Super::NativePreConstruct();


	canvasPanel = WidgetTree->ConstructWidget<UCanvasPanel>(UCanvasPanel::StaticClass(), FName("Canvas"));

	WidgetTree->RootWidget = canvasPanel;
	
	horizontalBox = WidgetTree->ConstructWidget<UHorizontalBox>();//NewObject<UHorizontalBox>();
	uploaderNickNameTextBlock = WidgetTree->ConstructWidget<UTextBlock>();
	uploaderTextBlock = WidgetTree->ConstructWidget<UTextBlock>();


	horizontalBox->AddChildToHorizontalBox(uploaderNickNameTextBlock);
	horizontalBox->AddChildToHorizontalBox(uploaderTextBlock);
	canvasPanel->AddChildToCanvas(horizontalBox);

	canvasPanel->AddToRoot();

	uploaderNickNameTextBlock->SetText(FText::FromString("Uploader:::"));
	uploaderTextBlock->SetText(FText::FromString("Mytext921382131928318"));