Hi Flavio!

The author's permission is not required. Currently, we have the following steps to publish a translation: 

  1. Publish your translation as an article/announcement on DC of the language you need
  2. Go to the original post, click on the Language Switcher icon on the left and choose the language you need 
  3. Provide a link to your translation in the related section. Our team will approve and link your translation to the original post. 
  4. After your post is linked to the original, you will receive an email notification.

In this article, you can find some screenshots of how to do that. 

Hope this helps!