Customer need end to end sample with OKTA auth

Customers need end to end sample with OKTA auth with custom headers propagation end to end
I am submitting this issue to submit a PR for this use case to this repo

Start by reviewing the repository's existing authentication and gateway samples to find the relevant entry points for an end-to-end flow. Define the sample around Okta authentication and custom-header propagation, then verify that both work across the complete flow; no specific files or tests are named in the issue.

Written by the indexing model from the issue text.