Add channel to contact

curl --request POST \
  --url https://api.zavu.dev/v1/contacts/{contactId}/channels \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "channel": "email",
  "identifier": "john.work@company.com",
  "label": "work"
}
'

{
  "channel": {
    "id": "<string>",
    "identifier": "+14155551234",
    "isPrimary": true,
    "verified": true,
    "createdAt": "2023-11-07T05:31:56Z",
    "countryCode": "US",
    "label": "work",
    "metrics": {
      "successCount": 123,
      "failureCount": 123,
      "totalAttempts": 123,
      "avgDeliveryTimeMs": 123,
      "lastSuccessAt": "2023-11-07T05:31:56Z"
    },
    "lastInboundAt": "2023-11-07T05:31:56Z",
    "metadata": {},
    "updatedAt": "2023-11-07T05:31:56Z"
  }
}