An Azure OpenAI key is not a drop-in for an OpenAI key

Azure OpenAI issues a key that looks like a generic secret but is not interchangeable with a platform.openai.com sk-... key: auth is the header api-key: <key> rather than Authorization: Bearer, the request path addresses a DEPLOYMENT name rather than a model name, and an api-version query param is mandatory. Anything expecting a stock OpenAI key silently fails on all three. Before provisioning, run az cognitiveservices account list --query "[?kind=='OpenAI']" — the resource frequently already exists, and listing its keys is read-only while creating one is a billable action. A key alone proves nothing: pair it with az cognitiveservices account deployment list, because a resource with zero model deployments returns a valid key that cannot serve a single request.