在php回声中转义html标签

Question

我有一个AJAX联系表单，在成功消息中我想添加html标签，但是当我这样做时，它会打印标签，因此它显示为......

  <p>Thank You! You are unsubscribed.</p>

我该如何修改以下内容？

    if (mail($recipient, $subject, $email_content, $email_headers)) {
        http_response_code(200);
        echo '<p>Thank You! You are unsubscribed.</p>';
    } else {
        http_response_code(500);
        echo "Oops! Something went wrong and we couldn't send your message.";
    }

它看起来并不像How to echo in PHP, html tags

那么容易

我无法集成document.write