curl --request GET \
  --url https://api.letpiper.com/v1/orgs/{org_id}/credentials/{key}/usage \
  --header 'Authorization: Bearer <token>'

{
  "llm_providers": [
    {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "provider": "<string>"
    }
  ],
  "domains": [
    {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "domain": "<string>"
    }
  ]
}