Response in Forward Auth failure

I have a question wrt forwardauth. When there is an auth failure, the auth server sends 401 along with some JSON body (error code, error message etc).
Question is whether the traefik forwards the response body as well along with 401 back to the client/source?

The message from client comes on wss.

According to the doc:

The ForwardAuth middleware delegates authentication to an external service. If the service answers with a 2XX code, access is granted, and the original request is performed. Otherwise, the response from the authentication server is returned.