External does not work when attempting to link to a section on a different page

I have read all the blog posts and watched youtube videos on this topic but the link still does not work.

Issue: the navigation link I am attempting to link back to the home page does not work when I attempt to preview the link I get sent to a 404 page. When I searched the page setting for the exact ‘Slug’ for the web URL…it seems this feature has been removed from the interface altogether. I have an issue because I cannot get my navigation links to work as I want.

I want to link a navigation link from my about page back to the home page ‘section’ service but, keep the home page nav link and have it go to the actually on the page. Now this guy video is an example of what I am trying to accomplish but unable to.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)