Hi Flavio, thank you really much for your help;
it worked immediately, but i would like to know how i can give an order to it (it’s appearing at the right part, and i want to be between 03 and 05)
You could just hardcode the navigation you want there, or do some fancy things like adding a url property in the yaml frontmatter of a page, and do <a href="{{ page.header.url ?: page.url }}"> in your customized template navigation twig.
In this way those pages with (for example) url: http://test.com will be redirected to the specified url.
An easier option would be to create a dummy page so you get the menu where you want it in the order you want, then set a redirect in your site.yaml file for that route.
Another question: there is a way to show the content of the link in the same theme without exiting from it ? (like the grav forum), maintaining the navigation bar on top
no, no, i want to mantain the top navigation bar but with the content of another page, like the forum (same navigation bar like the website but forum content) Schermata 2015-09-20 alle 20
What page though? A non-grav page? you want to pull it into the Grav site? The forum on this site is just a grav page that has some JS in it to pull display the forum. I guess you could have a Grav page with an iframe in it to load content from another URL, but you can’t really just show something there wrapped in Grav.