1. Hover over the header and click Edit section.
2. Add the navigation links you want to include in the drop-down menu.
3. Using the grip icon ⠿, drag each navigation link so it's below the navigation link you want it to drop down from.
Then move the link to the right of the list until the dropdown arrow ↳ appears and drop your link.
To check your navigation links are working, click Preview to test them out. If they're working, click Publish.