Shortcode not working on latest post page

The faq states :
If you are using “Your latest posts” as home page, you should paste this code <?php echo do_shortcode(“[pt_view id=VIEW_ID]”); ?> to a theme file: front-page.php or home.php or index.php.

I have not added any pages to my wordpress theme, im only using the latest post page. The problem I am having is that when I add <?php echo do_shortcode(“[pt_view id=VIEW_ID]”); ?> to the end of my theme (index.php) file, no changes occur.

What am I doing wrong?

Thank you