将可点击的电话号码添加到php邮件

I have a website form that submits data to php the I use POST to send that data to my email. Currently when I do this the phone numbers are clickable and it would be more convenient if I can click on the phone number as it lands in the email and make the call.

Tried to add a href link for tel: but added errors to code

$message = '';
$message .= '<div>First Name: ' . htmlspecialchars($_POST['fname']) . '</div>';
$message .= '<div>Last Name: ' . htmlspecialchars($_POST['lname']) . '</div>';
$message .= '<div>Email address: ' . htmlspecialchars($_POST['email']) . '</div>';
$message .= '<div>Phone: ' . htmlspecialchars($_POST['number']) . '</div>';

Figured it out..posting answer in case anyone else comes across the same problem.

$message .= '<div>Phone: <a href="tel:' . htmlspecialchars($_POST['number'])  . '">' . htmlspecialchars($_POST['number']) . '</a></div>';