Trigger multiple emails with REST

sfmc-rest-trigger-multiple-emails.txt

POST /messaging/v1/messageDefinitionSends/key:YOURTSDEXTERNALKEY/sendBatch HTTP/1.1
Host: YOURENDPOINT.rest.marketingcloudapis.com
Authorization: Bearer YOURAUTHTOKEN
Content-Type: application/json
cache-control: no-cache
[
    {
        "To": {
            "Address": "neo@example.com",
            "SubscriberKey": "1111",
            "ContactAttributes": {
                "SubscriberAttributes": {
                    "FirstName": "Neo"
                }
            }
        }
    },
    {
        "To": {
            "Address": "morpheus@example.com",
            "SubscriberKey": "2222",
            "ContactAttributes": {
                "SubscriberAttributes": {
                    "FirstName": "Morpheus"
                }
            }
        }
    }
]