How to place image to use as menu icon top right?

Hi, I’d like to add an image i created to act as the menu icon – 3 horizontal bars, to top right of site. I’ve tried uploading it thru the various Navigation image upload options. It only appears when “static” and size won’t render/change much playing with dimensions. Ideally for it to be quite large.

From there I’d like to link a menu up. Thought wp allowed image upload for menu in appearance but nothing there.

Thanks ??

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