The API key was issued for a different environment (production, QA or local dev) than the API it was sent to. 401, not retryable: use a key issued for this environment. The detail names both, for example "This API key is for QA, but this is the production API." Nothing was executed.
OPDC API error code
KEY_WRONG_ENVIRONMENT
HTTP status 401
The API answers with a problem document (RFC 9457) whose type is https://twinn.engineering/errors/key-wrong-environment, and with X-Error-Code: KEY_WRONG_ENVIRONMENT. Branch on the code, never on the detail text.