Here is an example of what a notification will look like once you have configured your endpoint and recorded a hit.

{
  "Type" : "Notification",
  "MessageId" : "13a9afd1-57b5-5c1c-80e4-f7a86d76c646",
  "TopicArn" : "arn:aws:sns:us-east-1:705477198468:ea_account_production_87",
  "Message" : "{\"activity_type\":\"Read\",\"campaign_guid\":\"rykxueap\",\"custom_id\":\"\",\"custom_data\":\"[UNIQUE]\",\"custom_type\":\"\",\"lat\":\"34.0007\",\"long\":\"-81.0348\",\"city\":\"\",\"region\":\"South Carolina\",\"country\":\"United States\",\"referrer\":\"\",\"user_agent\":\"Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko Firefox/11.0 (via ggpht.com GoogleImageProxy)\",\"created_at\":\"2021-01-13T18:13:26\",\"mail_client\":\"Gmail\",\"mail_client_specific\":\"Via Gmail's Image Cache\",\"rendering_engine\":\"Webkit\",\"platform\":\"webmail\",\"read_category\":\"GlancedOrUnread\",\"read_seconds\":0}",
  "Timestamp" : "2021-01-13T18:14:27.040Z",
  "SignatureVersion" : "1",
  "Signature" : "nLMmLBFsz9Ye+7IsHUQsr32gnrZl9vc+B6Ptbh0lrpTEmNg+tCa6JrTANcn21te9CVbwt9Tqg9KFUl08r2bSk2EgzEwCOkzqvxKWhIHL6hDePmNmv6gqRO+U6Ko+wRFhbs7y7+vvCc4Ngyf/ivvaO84I8iecE9GAwLzZT+H3/d0CP4hVskvuBDVHUpqwV4IIQJm9qTzHNoL2LO7Be9HIBD03Ck2W9TRj9oaTcWZc5ySu2RJDL7RieIX6UsCPAVX+vSiWsQ0rnn6q03I0P1k/iM5mtsD7M2manYehuS2gYET8y9pKN2tvC8BREPmvx0cCXTVAFqO51xh9dpM5JvHDiQ==",
  "SigningCertURL" : "https://sns.us-east-1.amazonaws.com/SimpleNotificationService-010a507c1833636cd94bdb98bd93083a.pem",
  "UnsubscribeURL" : "https://sns.us-east-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:us-east-1:705477198468:ea_account_production_87:9ad5896f-f038-4bc4-98ba-9b9f4659b1b2"
}