I originally experienced it when I wanted to create a dropdown submenu and didn’t want to have a page.
One way to do that is to add #
in the URL field on that top-level item. Unfortunately, that has negative implications for accessibility, so that’s something to bear in mind. There’s more info and alternatives here: https://css-tricks.com/how-to-disable-links/
Lately, I would like either a separator such as used in bootstrap and now I would like to create header text.
There’s no built-in way in WordPress (either with block themes that use Site Editing like Twenty Twenty-Two, or classic themes) to add separators in menus. Typically you’d either need a plugin or custom CSS for that.
If you can provide a link to your site and show me where you want to add the separator, I’d be glad to have a look directly.
I’m not sure what you mean by adding header text in your menu, could you perhaps show me an example of what you mean? Thanks!