Access Denied Error

I followed a couple of tutorials and setup a Kinesis Agent > Kinesis > Lambda > ES (EKK instead of ELK stack) and I ran into the following response using the code.

Response:
Unable to determine service/operation name to be authorized

After hours of searching, I found this thread ( http://www.philliphaydon.com/2016/01/03/using-aws-api-gateway-and-sqs-to-recieve-sendgrid-event-hooks/ ) that said to send the payload as a form. Sure enough, the error went away and I could talk to ES.