Hello @galeriteam,
The Header image you are referring to is placed in the demo of the site using the MP:Image widget in the Header Right Widget Area.
You should be able to set your desired image in the section using the widget area / widget. Please check and verify you have properly used implemented the widget in the widget area.
To get the same effect as the demo of the site, please leave the title field in the image widget empty.
Quick Tip : If you have enabled any Ad blocker extensions in your browser, the section will be removed by the browser as the blockers targets such header images. To properly verify the issue, please try disabling the adblocker extension or browse in incognito mode.
Also, for the documentation of the theme please follow the link here : https://themepalace.com/theme-instructions/magazine-plus/
You can also post in your queries in the theme’s official forum for dedicated and swift support at : https://themepalace.com/forum/magazine-plus/
Hope this helps,
Best Regards !!