curl --request POST \
  --url https://restapi.sign.plus/v2/webhooks \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "webhook_id": "<string>"
}
'

{
  "webhooks": [
    {
      "id": "<string>",
      "target": "<string>"
    }
  ]
}