How can I add the flags to the secondary menu in my header?

Q: How can I add the flags to the secondary menu in my header? I have created the menu but I need your assessment to tell me how to add the plugin to that section.

A: You can fix it going to the editor and adding

register_nav_menu('header', 'Header Menu');
register_nav_menu('ad-menu1', 'Ad Menu One');

inside of the function.php

Source.