My Latest Tweet in a Text Widget Problem

I’ve included the recommended text from My Latest Tweet as a text widget viz.

<?php if(function_exists(‘_mw_lt_update’)) _mw_lt_update(); ?>

but nothing shows up in the sidebar of my blog. Any ideas? The plugin is activated and I’m using the default text setting. Home page for the plugin is https://meyerweb.com/eric/tools/wordpress/mw_latest_tweet.html