First, you have to complete the kata in any of the available languages. Then, you can click on the translations tab near the top of the page, and click on the translate button. Then, you have to program the kata in your language of choice and publish the translation. Documentation on the testing libraries and methodologies is not super great, I suggest looking at translations done for other kata in your language to get a better grasp on it. Notably, one of the mods has a small collection of kata that exemplify best practices for programming kata available in most (if not all) available languages on codewars. You can find that here

After that, it's a good idea to leave a new comment here in the discourse with the "suggestion" tag with a link to your translation. Either the kata's author or another user will have to approve your translation before it can go live.

I suggest reading the translation authoring guidelines, and it wouldn't be a bad idea to read all of the docs in the authoring section (even though not all of it will apply to translations). It's also a good idea to join the codewars discord so you can post a link to your completed translation in the "reviewing" channel, and get help in the "help-translate" channel. The discord will get you a lot more visibility on your translation.

No user translated this challenge to Java, C, C++, or JavaScript. Feel free to do so if you think that these languages are missing ;)