我有以下代码：

<?php
$post_data['firstname'] = '';
$post_data['lastname'] = '';
$post_data['address'] = '';

foreach ( $post_data as $key => $value)
{
$post_items[] = $key . '=' . $value;
}

$post_string = implode ('&', $post_items);
$curl_connection = curl_init('https://example.com/app.php');
curl_setopt($curl_connection, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($curl_connection, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)");
curl_setopt($curl_connection, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl_connection, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($curl_connection, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($curl_connection, CURLOPT_POSTFIELDS, $post_string);
$result = curl_exec($curl_connection);
echo "Result: " . $result . "<br><br>";
print_r(curl_getinfo($curl_connection));
echo curl_errno($curl_connection) . '-' . curl_error($curl_connection);
curl_close($curl_connection);
?>

如何将其连接到HTML表单，以便某人可以在HTML页面中输入其详细信息，并且其值将被重定向到此PHP代码？
我的HTML代码是：

<form name="form" method="post" action="my_php.php">
<input name="firstname" type="text" ID="firstname" value="first name">
<input name="lastname" type="text" ID="lastname" value="last name">
<input name="address" type="text" ID="address" value="address">
<input type="submit" name="Submit" value="Submit">