Need tutorial - how to set up the Top Keyword for Page URL

Hi, I am new to Piwik. Alsthough I am not new to dashboard based analytic systems. I have tried several times, unsuccessfully to install the “Top Keyword for Page URL” widget. Where does the PHP code go? I am trying to get it to work on a Wordpress based site. I have installed the code in my main page template php file. However it simply doesn’t work.

Does anyone have any tips or perhaps a link to a tutorial on how to get it to work? I see other users have had the same question. But nobody has ever posted an answer? Does this function indeed work?

Thanks in advance.