Menu

Hi, I installed in my new domain Lingotek and Polylang.
But I can’t insert in the main menu the option “choose language” like other sites. I don’t know why it doesn’t let me .
https://oi67.tinypic.com/16ih3rc.jpg
How you can see in my olt site I can use is , but in my new site I can’t.
This is the new site: https://www.agep1989.ch/
Old site: https://www.agep1989.ch/agep.ch/