Hello, @Jubaer,
Actually, You didn’t share your site access with us so I made a video from our test site for you to know how you can add a widget you want in the header. Here is the video link: https://www.veed.io/view/876dac39-227a-4ae3-a8ba-0f0565e932d0?sharingWidget=true I hope you understand and fix your issue.
Have a nice day.
Regards 8Themes Team.