How to add language switcher in Polylang plugin
You can include the Polylang language switcher in your menu.
To add the language switcher:
1. From the WordPress left menu, go to Appearance > Menus.
2. Click on Language Switcher, and then click on the Add to Menu button.
3. Click on the Save Menu button.
Note: If you don’t see Language Switcher item, open Screen Options at the top and tick the “Language Switcher” box.