Hello,
To change breadcrumbs image for Category go to Categories > upload Custom page heading image for this category.
If you want to use different breadcrumbs images for some pages instead of the image that were selected in Theme Options then go to Pages > edit page > upload featured image for your page and it will appear in breadcrumbs. Also, every page has its own breadcrumbs settings, edit page and scroll down to 8theme – Layout settings > http://prntscr.com/gwfdca
Feel free to ask if you have any other questions.
Regards