curl --request DELETE \
  --url https://api.example.com/api/ScheduledMessages \
  --header 'Content-Type: application/json' \
  --data '
{
  "emails": [
    {
      "messageId": 123,
      "entityId": 123,
      "playerId": 123
    }
  ],
  "sms": [
    123
  ]
}
'