1 Click A Custom Code → Global Menu.
2 Type a group name that you can identify or remember the next time.
3 Select a Template.
4 Select with specific Pages/Post by entering 3 or more characters (Leave this field empty if you want every single posts of your entire website).
5 Select a Selector.
6 or Type your selector whether it is tag, id or class.
7 Apply Your Styling.
8 You can load External Libraries.
9 Also you can add CDN Link.
10 Also you can add CSS Code.
11 Also you can add JS Code.
12 And then click on→ Save button.