WP-TweetButton is not displaying the tweet button if this is set to “Manual.” [closed]

Looks like you’ve mis-named the function. It is the_tweetbutton(), rather than tweetbutton().

Also, you should always wrap Plugin-added function calls in if (function_exists()) conditional wrappers.

Putting that together, this:

<div id="tweet-button">
      <?php tweetbutton(); ?>
</div>

Becomes this:

<div id="tweet-button">
      <?php if ( function_exists( 'the_tweetbutton' ) ) the_tweetbutton(); ?>
</div>