Next, from the Ribbon menu, select the ‘Design’ tab and choose ‘Watermark’ from the ‘Page Background’ section. Hit the drop-down arrow to choose the desired layout and then right-click ...

With your document open, select the "Design" tab. Then, click the "Watermark" button in the Page Background group of that tab, and choose one of the built-in watermarks in the resultant drop-down ...