Language switcher doesn’t work

Hi,

I use polylang for my customer-site https://www.monikalaschkolnig.com. The first language is english, the second one german.

I can create the pages in both languages. But

I cannot assign the Language Switcher to my menus because it is not displayed.

Following steps I have already done:
* Deactivating all plugins except Polylang
* Changing the theme
* Deactivating browser language detection

Nothing works.

I saw, that there some support messages for this topic. Do you have any solution for this problem?

Best regards,
Daniela

The page I need help with: [log in to see the link]