curl --request GET \
  --url https://dev-billing-api.spectertech.ai/api/v1/plans/{id}

{
  "id": "<string>",
  "name": "<string>",
  "description": "<string>",
  "price": 123,
  "currency": "<string>",
  "interval": "<string>",
  "features": [
    {
      "id": "<string>",
      "name": "<string>",
      "description": "<string>"
    }
  ]
}