Hi @mark.boyd,
The example above is to “illustrate” what header is expected for proxy authentication by OpenSearch how you add it, is completely up to you. You can bypass it or configure your reverse proxy to do so.
Isn’t bypassing proxy authentication what you are trying to achieve with “basic auth”, correct?
Note: proxy is unsupported with “multiple_auth” on Dashboards.
As for securing your cluster, I would strongly advise enabling TLS, see more here: Configuring TLS certificates - OpenSearch Documentation
Best,
mj