How to submit my wiki articles with option for translation?

I see some of your wiki articles have an option to translation, so any member can translate your wiki articles to proper languages. But When I try to submit one article, I find on such option.

How can I add that translate function?

Hi pluiepoco. Only the articles used for the website user interface are able to be translated this way.
The wiki articles you create can be translated too, but they don't appear in the list. You can also create a project if you have texts you want to translate without spending points but it's the same rule, project translations don't appear in the main flow of requested translations, despite you can ask for help to some generous members who are willing to help without earning points.

I really find that translate button on the left! Thank you!

As to project translation, let me investigate!