curl --request POST \
  --url https://api.zavu.dev/v1/broadcasts/{broadcastId}/cancel \
  --header 'Authorization: Bearer <token>'

{
  "broadcast": {
    "id": "brd_abc123",
    "name": "<string>",
    "status": "draft",
    "channel": "smart",
    "messageType": "text",
    "totalContacts": 123,
    "createdAt": "2023-11-07T05:31:56Z",
    "text": "<string>",
    "content": {
      "mediaUrl": "<string>",
      "mediaId": "<string>",
      "mimeType": "<string>",
      "filename": "<string>",
      "templateId": "<string>",
      "templateVariables": {}
    },
    "senderId": "<string>",
    "emailSubject": "<string>",
    "pendingCount": 123,
    "sendingCount": 123,
    "deliveredCount": 123,
    "failedCount": 123,
    "estimatedCost": 123,
    "reservedAmount": 123,
    "actualCost": 123,
    "scheduledAt": "2023-11-07T05:31:56Z",
    "startedAt": "2023-11-07T05:31:56Z",
    "completedAt": "2023-11-07T05:31:56Z",
    "metadata": {},
    "updatedAt": "2023-11-07T05:31:56Z"
  }
}