move everything previously under the central widget into the first page of the stacked widge

[lse123]

My book says create stacked widget and to a Page of this Add: move everything previously
under the central widget into the first page of the stacked widget.... as I append text below... ... I have the screenshot attach below... // How insert the blue widgets to loginPage shown by arrows... ? Why is the RED ICON in loginPage? Tried cut/copy and paste but getting the >> // What to do ... ?

Since the previous login page was not made with a stacked widget in mind, we have to
make some adjustments to it. First, drag and drop a stacked widget from the Widget Box to
the central widget of your application, and then, we need to move everything previously
under the central widget into the first page of the stacked widget, which we
renamed loginPage:

[jsulm]

@lse123 Do what the dialog tells you to do: break the layout in your login page and then drag and layout again.

[lse123]

what means "Break the layout"
and how do this, where is in the menu or content menu... ?