{
"to": "test@email.com",
"transactional_message_id": "15",
"send_at": 1644597600, // unix timestamp format ex: ($date = new DateTime('2022-02-11 20:40:00'), $date->getTimestamp())
"message_data": {
"userName": "Kira",
"userEmailAddress": "test@email.com",
"StartDate": "test date",
"TimeRange": "test range"
},
"identifiers": {
"id": "2332"
}
}