The statement that is incorrect is: "The request does not require an Authorization header." In order to POST messages to a stream in the OCI Streaming service using OCI APIs, the request does require an Authorization header. The Authorization header is used to provide authentication and ensure the request is authorized to access the stream. The correct approach is to include the Authorization header in the request, along with other required headers such as x-content-sha256, content-type, and content-length. Therefore, the incorrect statement is that the request does not require an Authorization header.\