what does mean x or '0'?

Initial setup is wrong (from solution import sum)

Right now, nothing. It was retired because it got 4 not satisfied votes in a row. Writing a new kata isn't an easy task, you should come up with a novel idea at least, read the docs as a first step on authoring a kata: https://docs.codewars.com/authoring

Ok, and what i must to do?

As hobovsky wrote in another kata:

"Duplicate" does not mean that the kata is a copy of another kata. Duplicate means that this kata presents exactly the same problem, and even can be solved with exactly the same solution, as another, already existing kata.

Maybe kata like my there is, but my kata was completely made by me.

Duplicate?