Adding Custom Link anchors in the top menu that points to specific sections of the site home page

If all you want is to go to a specific section of the home page, then the easiest way is to use the relative URL mark / and then use the anchor #xxx.

So the custom link for the menu will be: /#xxx.

Note the difference between #xxx and /#xxx as custom link.

The best thing about this approach is that you’ll not have to bother changing the link after you go live, and additionally, this needs no programming.