Can't see any other languages

I've installed the plugin and have translated one of the posts to all languages, but I don't see the selected language.

For example, I've tried with /fr/ but get nothing.

Here is a page that has had everything automatically translated to all languages:

If I try I just get a 404 page, if I try to do it for indsividual posts, the /fr just gets removed.

Also, using the widget doesn't change anything, it just reloads the page in English. You can see the widget at the top right of every page, in the sidebar.