Unable to add image to header [Symmetry Theme]

I’m using “Symmetry” theme for my shop and would like to have an image as the background of the header (as shown in many Symmetry examples) with a transparent menu on top. When I am in my theme editor and go to the “header” section there is nowhere for me to add a background image. Am I missing something, is there another location where I add this? Perhaps I changed the code at some point and now can’t add an image in this spot? Help!

Below is a screenshot of the Symmetry theme with an image as the header background - this is the format I am trying to achieve.

Hi @ekfarina wrong self diagnosis and approach https://xyproblem.info/ .

Just because something is near the top of a page doesn’t make it a header or part of a header.

Just add a different section that is relevant to showing image or other media in the theme editor.

Read the manual https://help.shopify.com/en/manual/online-store/themes/customizing-themes/edit?q=theme+editor

And probably watch some theme setup tutorial videos online to aid with clarifying expectation misconceptions.