protocol
The protocol that you want to use. Supported protocols include:
http– delivery of JSON-encoded message via HTTP POSThttps– delivery of JSON-encoded message via HTTPS POSTemail– delivery of message via SMTPemail-json– delivery of JSON-encoded message via SMTPsms– delivery of message via SMSsqs– delivery of JSON-encoded message to an Amazon SQS queueapplication– delivery of JSON-encoded message to an EndpointArn for a mobile app and devicelambda– delivery of JSON-encoded message to an Lambda functionfirehose– delivery of JSON-encoded message to an Amazon Data Firehose delivery stream.