How can I make the header Like button to work p...

There is a simple way of setting the social widget’s unique URL, so that it counts the likes and tweets. Modify the data-url attibute on the addthis_toolbox container like this (in the #header of each file):

<div class="addthis_toolbox addthis_default_style" data-url="http://myurl.com">
    <a class="addthis_button_facebook_like"></a>
</div>

Please see the AddThis widget documentation for this matter.