How can the code provided be modified to properly include the text file in the HTML page?

The code provided is missing the PHP code to read the contents of the text file and include it in the HTML page. To fix this, we need to use the `file_get_contents()` function to read the text file and then echo the contents within the HTML page.

<?php
$file = 'example.txt';
if (file_exists($file)) {
    $content = file_get_contents($file);
    echo "<p>$content</p>";
} else {
    echo "File not found.";
}
?>