Adding an HTML widget/box below header?

Is there a way to add a full width html widget or area below the header but above the main content area? See the attached screenshots as an example. The screenshot with the ad is what I am trying to achieve (it is my old site)

Hi there

Im sorry, but that’s impossible without modifying the template. There is no such option

Thank you for the quick response. I think I figured out how to modify the template to do so.

Hi @jasimin65

You need to manually make such changes, this needs a custom development