To access it you have to navigate to the PixiePanel / Header / Header settings

Admin Panel → PixiePanel → Header → Header Settings

Here you can hide or show the search in the header.

News header background

Here you can upload the banner image for the news page. The size required is: 1920x600

404 background

Here you can upload the banner image for the 404 page. The size required is: 1920x600