This code enables you to change your header image for each category archive page like this:
Simply upload a different image to your child themes images folder with a file name matching what’s in the code. In this example you’ll find 1.png for category-1, 2.png for category-2, 3.png for category-3 and so on.
The default header image added via the WordPress customizer is used for all other pages.
The code works in any theme.
Here’s the code for logged in members: