curl --request PUT \
  --url https://api.interchange.io/api/v2/notification-preferences \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "optIns": [
    {
      "notificationType": "brand_agent.created",
      "channel": "email"
    }
  ]
}
'

{
  "data": null,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "field": "<string>",
    "details": {}
  }
}