curl --request POST \
  --url https://api.simpu.co/sms/send \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "channel": "sms",
  "recipients": "2348023456789, 2348098765432",
  "sender_id": "Simpu",
  "content": "Hello! World. This is a test message.",
  "template_id": "674535b2b39158b9aae90188fcec23eb",
  "personalisation": [
    {
      "to": "2348023456789",
      "substitutions": {
        "name": "John Doe"
      }
    }
  ],
  "external_ref": "674535b2b39158b9aae90188fcec23eb",
  "is_trackable": false,
  "callback": "https://example.com/sms/delivery_report"
}'

{
  "id": "674535b2b39158b9aae90188fcec23eb",
  "recipients": [
    "2348023456789"
  ],
  "sender_id": "Simpu",
  "is_trackable": false,
  "content": "Hello! World. This is a test message.",
  "external_ref": "674535b2b39158b9aae90188fcec23eb",
  "callback": "https://example.com/sms/delivery_report",
  "template_id": "674535b2b39158b9aae90188fcec23eb",
  "personalisation": [
    {
      "to": "2348023456789",
      "substitutions": {
        "name": "John Doe"
      }
    }
  ],
  "created_datetime": "2024-06-28T23:56:38.128604+00:00",
  "updated_datetime": "2024-06-28T23:56:38.128604+00:00",
  "meta": {
    "method": "POST",
    "resource": "/send/sms",
    "estimate": {
      "available_balance": 1000.5,
      "charge": 3,
      "encoding": "UTF-8",
      "message_length": 160,
      "pages": 1
    }
  }
}