FastAPI instrumentation - how "traceparent" header works?

[JobaDiniz]

I don't see in the documentation of opentelemetry-instrumentation-fastapi whether traceparent header is supported.

1. Does this header is returned to the client in the response headers? If not, how can I set this?
2. If a client sets traceparent (is that the header name?) header, does the automatic fastapi instrumentation use this to set the correct trace parent/context? I couldn't figure out from the source code.