In the event you need to add a page to the top menu of the site, in the left hand column hover over the appearance and click on Menus:
Next select the top menu:
You will get:
If you can’t see the page you want to add, click on view all. You can also search for the page. I am going to add Contact us. Check the Contact us:
Then click on add to menu.
Finally, click on save menu.
The menu item is now present:
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