[Решено] Add Menu language switcher

Background of the issue:
I am trying to add a menu language switcher in my menus on my site скрытая ссылка.

Symptoms:
The button for the Menu language switcher is grayed out and it says there are no menus in the site, but there are.

Questions:
Why is the Menu language switcher button grayed out?
Why does it say there are no menus when there are?