Dashboard Footer Content

Hi,
on http://www.zijemehomemade.cz I activate Ultimate Branding plugin. I activate "Dashboard Footer Content" and write text "© 2018 http://www.zijemehomemade.cz ..."
But in the footer of the website is still "Designed by Elegant Themes | Powered by WordPress"
I use Extra Theme (child theme).
How to fix it?
Thanks,
Jiri