syntax error, unexpected '

Hi,

You’re receiving this error because you are trying to use the wrong sort of snippet with this plugin. It’s designed to work with PHP code snippets which don’t directly produce output, like you might find in a plugin or a theme’s functions.php file.

Fortunately, there is a way to convert your HTML code into a proper PHP snippet:

add_shortcode( 'twitter_conversation_count', function () { ?>

<!-- Twitter single-event website tag code -->
<script src="//platform.twitter.com/oct.js" type="text/javascript"></script>
<script type="text/javascript">twttr.conversion.trackPid('nuj9y', { tw_sale_amount: 0, tw_order_quantity: 0 });</script>
<noscript>
<img height="1" width="1" style="display:none;" alt="" src="https://analytics.twitter.com/i/adsct?txn_id=nuj9y&p_id=Twitter&tw_sale_amount=0&tw_order_quantity=0" />
<img height="1" width="1" style="display:none;" alt="" src="//t.co/i/adsct?txn_id=nuj9y&p_id=Twitter&tw_sale_amount=0&tw_order_quantity=0" />
</noscript>
<!-- End Twitter single-event website tag code -->

<?php } );

As you can see, all I have done is wrapped it in a shortcode function so you can just use the [twitter_conversation_count] shortcode in posts and pages. If you’d prefer to use a shorter and more meaningful name, just change the value in the code above.