Php echo is not working in my HTML woocommerce custom email - php

Question

I have a custom email which is triggered if product has meta in woocommerce order. Everything works great but I can't get the billing_first_name into the text. I use <?php echo $menomeno; ?>which is declared as $order->get_billing_first_name(); and I've also tried <?php echo $order->get_billing_first_name(); ?> Nothing worked, I get everytime empty string in the email. I have also tried to use sprintf method but it did not sent email. Any ideas how may I solve this?
Note: HTML code is shortened, its much bigger but I did not want to post the whole big code because its not neccesary in this situation when we need to get billing name in the part of the code.
function send_a_custom_email( $order_id, $order ) {
global $woocommerce;
$order = new WC_Order( $order_id );
$mailer = $woocommerce->mailer();
$product_ids = array( ); // Initializing
$customer_email = $order->get_billing_email();
$customer_name = $order->get_billing_first_name();
foreach ( $order->get_items() as $item ) {
$meta_data = $item->get_meta('meno'); // Zisti ake je meno
$venovanie = $item->get_meta('venovanie'); // // Zisti ake je venovanie
$product_id = $item->get_variation_id() ? $item->get_variation_id() : $item->get_product_id();
if( empty($meta_data) ) {
$product_ids[] = $item->get_variation_id() > 0 ? $item->get_variation_id() : $item->get_product_id();
}
}
if ( empty($product_ids) && $product_id == 2805 ) {
$recipient = $customer_email; // Set email recipient
$menomeno = $customer_name;
$subject = sprintf( __('Order #%d: Has missing item meta data'), $order_id );
$content = '<table border="0" cellpadding="0" cellspacing="0" class="text_block" role="presentation" style="mso-table-lspace: 0pt; mso-table-rspace: 0pt; word-break: break-word;" width="100%">
<tr>
<td style="padding-bottom:30px;padding-left:30px;padding-right:30px;padding-top:15px;">
<div style="font-family: sans-serif">
<div style="font-size: 14px; mso-line-height-alt: 25.2px; color: #ffffff; line-height: 1.8; font-family: Montserrat, Trebuchet MS, Lucida Grande, Lucida Sans Unicode, Lucida Sans, Tahoma, sans-serif;">
<p style="margin: 0; font-size: 16px; text-align: center;"><strong>S láskou <?php echo $menomeno; ?>
</strong></p>
</div>
</div>
</td>
</tr>
</table>';
//wp_mail( $recipient, $subject, $content ); // Send email
$mailer->send( $order->billing_email, sprintf( __( 'DTerapia s láskou' ), $order->get_order_number() ), $content );
}
}
Thanks in advance.

Answer 1

Please see this explanation about concatenation:
https://www.php.net/manual/en/language.operators.string.php