Send email after receipt upload

Question

I'm using this plugin: https://es.wordpress.org/plugins/pepro-bacs-receipt-upload-for-woocommerce/ and I want to send a email to the admin after a buyer upload a receipt. I have this code, but it's not sending emails, what am I doing wrong?

add_action( "woocommerce_customer_uploaded_receipt", "send_mail_after_bacs_receipt_uploaded", 10, 2);

function send_mail_after_bacs_receipt_uploaded($OrderID, $UploadedAttachmentID)
{
  global $Pepro_Upload_Receipt;

  $_image_url    = wp_get_attachment_url($UploadedAttachmentID);
  $_image_src    = wp_get_attachment_image_src($UploadedAttachmentID, 'full');
  $_image_src    = $_image_src ? $_image_src[0] : $Pepro_Upload_Receipt->defaultImg;
  $blog_name     = get_bloginfo('name', 'display');
  $blog_address  = parse_url(get_bloginfo('url'), PHP_URL_HOST);
  $blog_mail     = "wordpress@$blog_address";
  $admin_mail    = get_option('admin_email');

  $order         = new WC_Order($OrderID);
  $user_id       = $order->get_user_id();
  $current_user  = get_user_by("ID", $user_id);

  $mail_receiver = $current_user->user_email;
  $mail_subject  = "[$blog_name] BACS Receipt";

  $mail_wrapper_styles = "display:block;
  width:450px;
  border-radius:0.5rem;
  margin: 1rem auto;
  text-align: center;
  color: #2b2b2b;
  padding: 1rem;
  box-shadow: 0 2px 5px 1px #0003;
  border: 1px solid #ccc;";

  $mail_body     = "<div style='$mail_wrapper_styles'>";
  $mail_body     .= "<h2>BACS Payment Proof Received</h2>";
  $mail_body     .= "<p>Hello <strong>$current_user->display_name</strong>, We've received you BACS Payment Proof.</p>";
  $mail_body     .= "<p>We are cheking nearly thousand payments daily and yours is in the list too.</p>";
  $mail_body     .= "<p>Please be patient, thank you.</p><br />";
  $mail_body     .= "<a href='$_image_url' target='_blank'>";
  $mail_body     .= "   <img title='Click to enlarge' style='border-radius: 0.5rem;' src='$_image_src' width='400px' />";
  $mail_body     .= "</a><br />";
  $mail_body     .= "<p><strong><small>Copyright &copy; $blog_name ($blog_address), all rights reserved.</small></strong><br />";
  $mail_body     .= "<small style='color: #717171;'>THIS MAIL WAS SENT TO <i>$mail_receiver</i></small></p>";
  $mail_body     .= "</div>";

  $headers       = array(
                      "Content-Type: text/html; charset=UTF-8",
                      "From: $blog_name <$blog_mail>"
                    );

  // https://developer.wordpress.org/reference/functions/wp_mail/
  wp_mail( $mail_receiver, $mail_subject, $mail_body, $headers );
}