curl --request POST \
  --url https://api.agentic.scope3.com/api/v2/buyer/advertisers/{advertiserId}/test-plans/{testPlanId}/link-buys \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "allocationEntryIds": [
    "3c90c3cc-0d44-4b50-8888-8dd25736052a"
  ],
  "role": "test"
}
'

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