Hello,

I saw the screenshot you attached. To change the image of the shop page title background you need to edit the shop page and set the image according to your needs.

Screenshot for Clarification: https://ibb.co/ZdXv8CT

If you want to do it for separate categories then you need to edit that category and set the image accordingly.

Screenshot for Clarification: https://ibb.co/vkNdLys

Best Regards.