Send email after receipt upload - php

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 © $blog_name ($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 );
}