pll_preferred_language Not working

Hi,

Thanks for the great plugin.

I am trying to detect visiting user’s country and show my site in their language.

For example, if user is from France, i want to show my site in french. I used following code.

add_filter('pll_preferred_language', 'my_language_fallback1');

function my_language_fallback1($slug) {
	$IP=get_client_ip1(); //Get ip of visitor from a function (Works fine)
	$result=geoip_record_by_name($IP); // Get user details using this function (Works fine)
	$country=$result['country_name']; //Get user country (works fine).
	if($country=='France')
	{
		return $slug === false ? 'fr' : $slug;
	}
    else
    {
        return $slug === false ? 'en' : $slug;
    }
}

I tried with french proxy from internet and found no change in the site. Please help me to fix this issue.

https://www.ads-software.com/plugins/polylang/