Polylang don’t work properly

Polylang doesn’t quite work. The problem is that when I click the switcher from the default language to another, it redirects me to the general slug e.g.
I have the mywebsite.com/contact page and I click German in the switcher, instead of going to mywebsite/de/contact, it goes to mywebsite.com/de
And this problem is with every language.