The resource doesn't support specified Http Verb - azure-blob-storage

Question

I am trying to make a contact form for a static website hosted in an Azure blob.
When I click submit I can see the following error in the Console.
Failed to load resource: the server responded with a status of 405
(The resource doesn't support specified Http Verb.)
I think the issue may be that I need to set up CORS for mailgun.
However I don't know what values to put
Here is send.php code
<?php
if( isset($_POST) ){
$postData = $_POST;
$mailgun = sendMailgun($postData);
if($mailgun) {
echo "Great success.";
} else {
echo "Mailgun did not connect properly.";
}
}
function sendMailgun($data) {
$api_key = 'INSERT_API_KEY_HERE';
$api_domain = 'INSERT_DOMAIN_HERE';
$send_to = 'YOUR_EMAIL';
// sumbission data
$ipaddress = $_SERVER['REMOTE_ADDR'];
$date = date('d/m/Y');
$time = date('H:i:s');
// form data
$postcontent = $data['data'];
$reply = $data['senderAddress'];
$messageBody = "<p>You have received a new message from the contact form on your website.</p>
{$postcontent}
<p>This message was sent from the IP Address: {$ipaddress} on {$date} at {$time}</p>";
$config = array();
$config['api_key'] = $api_key;
$config['api_url'] = 'https://api.mailgun.net/v3/'.$api_domain.'/messages';
$message = array();
$message['from'] = $reply;
$message['to'] = $send_to;
$message['h:Reply-To'] = $reply;
$message['subject'] = "New Message from your Mailgun Contact Form";
$message['html'] = $messageBody;
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $config['api_url']);
curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($curl, CURLOPT_USERPWD, "api:{$config['api_key']}");
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS,$message);
$result = curl_exec($curl);
curl_close($curl);
return $result;
}
?>
This question is a follow up from this question
I have tried including the subdomain www in the api_domain.

Answer 1

PHP does not run client side which means it is not suitable for a static website. As mentioned in this question
Alternatives are mentioned here