curl --request GET \
  --url https://api.agentic.scope3.com/api/v2/buyer/advertisers/{advertiserId}/test-plans \
  --header 'Authorization: Bearer <token>'

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