How can I drag and drop a created widget into another widget in 5.4 and make it a public variable

In 5.4, if I create a widget and want to place it in another MainWidget, I can refer to it through MainWidgets in other blueprints. Widgets created by users who drag and drop it in UE4 are default public, not in 5.4. Additionally, in 5.4, I cannot create generic basic buttons or text, so I don’t need to repeatedly modify their styles. The buttons or text blueprints I created cannot be searched in the controls
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