curl --request PATCH \
  --url https://api.zerion.io/v1/tx-subscriptions/{subscription_id}/callback_url \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "callback_url": "https://webhook.site/new-callback-url"
}
'

{
  "errors": [
    {
      "title": "Parameter is malformed",
      "detail": "Some validation errors will be described here"
    }
  ]
}