Language switcher on Headermenu

Hi Forum,
I am using Polylang plug-in on Hueman Theme. I haven’t be able to find a way to add the language button (switcher) to te navigation bar (headermenu). I see there are some suggestions from customizr support about modifying the php.functions file, but they apply to customzr theme and not to hueman one. Anyway, I wonder if there is any method to render the navigation menu more flexible, possibly without messing up with the php.functions file like in customizr. Why cannot widgets simply be added to a headermenu? Especially the language button finds its best place there. Besides, also the search option is confined to the left of the menu, but I remember having it on the right. I do not know what´s happened, but I can’t find a way to shift the search option to the right side of the menu.
In short, I see Hueman has some limits with the customization of the headermenu. Has anyone having similar issues? Any suggestion will be welcome.
Thanks for replying

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