Add custom share link to post page (resp. product detail page)

Hi,

I could not find solution for adding custom share link. I need to add messenger icon and FB url with send argument. I found on forum this one
/*
* Add items on the social share section
*/

add_filter(‘avia_social_share_link_arguments’, ‘avia_add_social_share_link_arguments’, 10, 1);
function avia_add_social_share_link_arguments($args)
{
$args[‘Messenger’] = array(“encode”=>true, “encode_urls”=>false, “pattern” => “https://www.facebook.com/dialog/send?app_id=2110525345925438&link=%5Bpermalink%5D&redirect_uri=%5Bpermalink%5D”);
return $args;
}

But this is not exactly what i am looking for

How can i add custom share link with custom URL adress and also custom icon image?

Jakub