The Language Manager allows you to define the language for every individual Confluence page and blog post. This is needed to link the translations with each other.
How to define the language of a page
Navigate to the page or blog post of your choice.
Click on the three dots context menu 
button. A context menu will open. Now, click on the Language Manager button.
A new window called Manage Language Links will open. Here, click on the Select language drop-down menu next to the name of the page/blog post.
Enter the language of your choice. You can either type in the language or choose from the list.
Click the Save button after you chose the language.
A pop-up dialog will appear. You should reload the page to see the changes.
Link to this page: https://seibert.biz/lamadefinelanguage