How to change/edit URL link of CMS page?

[tonisky]

Hi guys, I am using latest Prestashop 1.7.4.2. I got a simple question here: how to change or edit URL link of CMS page? I want to put a CMS category on top menu, under the CMS category, there will be a few CMS topics. I want to change the url link of these CMS pages.  I attach a photo for better understanding.  As you see I created a CMS category called "About Us", under this category there will be a few topics: topic 1, topic 2....  I want to link theses topics to other external links.

I know in Top Menu module we can create new link and add to top menu, but it an only add individual page, It can't add category to the top menu.

Any help would be very appreciated.