1. Make sure you are in development mode, that means at the end of your HTML file you should be included the "js/index" instead of "js/index.min".
2. Opn your HTML file where the menu is defined and add the "js-external" class on all the external menus, like shown in the screenshot.
3. Open the "js/modules/menu.js" file and go to the "bindNavsAction" definition and change the selector as shown in the screenshot.
4. Now all the menus with the "js-external" class will redirect to the given "href".