You can have SNS send a post request when it gets a notification. But Amazon may want you to verify that this is really your endpoint before it'll work.

You can use something like this to verify it:

https://github.com/npflood/AWS-SNS-HTTP-PHP-ENDPOINT/blob/master/receiver.php

Or just a simple thing like this:

<?php

$res = file_get_contents("php://input");
file_put_contents("logs/response.txt", $res . "\n", FILE_APPEND);

Then you can read the response file for SubscribeUrl, e.g.:

{
  "Type" : "SubscriptionConfirmation",
  "MessageId" : "165545c9-2a5c-472c-8df2-7ff2be2b3b1b",
  "Token" : "2336412f37f...",
  "TopicArn" : "arn:aws:sns:us-west-2:123456789012:MyTopic",
  "Message" : "You have chosen to subscribe to the topic arn:aws:sns:us-west-2:123456789012:MyTopic.\nTo confirm the subscription, visit the SubscribeURL included in this message.",
  "SubscribeURL" : "https://sns.us-west-2.amazonaws.com/?Action=ConfirmSubscription&TopicArn=arn:aws:sns:us-west-2:123456789012:MyTopic&Token=2336412f37...",
  "Timestamp" : "2012-04-26T20:45:04.751Z",
  "SignatureVersion" : "1",
  "Signature" : "EXAMPLEpH+...",
  "SigningCertURL" : "https://sns.us-west-2.amazonaws.com/SimpleNotificationService-f3ecfb7224c7233fe7bb5f59f96de52f.pem"
}

When you click "Confirm Subscription" in AWS SNS, it wants you to enter SubscribeUrl.