How to Delete Add to Anti-Banner ?

That’s not part of the theme as seen on the WP demo
Disable your plugins. You probably added a plugin then forgot about it.

I don’t understand what you’re saying. Are you saying that it’s not a plugin?
Did you edit the theme files. Maybe you should just reinstall the theme if you’ve edited it.

If you still can’t remove that text on your site then you can try to hide it by adding this on your css: .kisb {display: none;}