How to set a custom header when requesting HTTP URL?

This is using the Smart Test Recorder, not the RESTful API testing. The first step in the test is “Navigate to {URL}”. I want to define extra HTTP headers to be sent in that request?

So the step would do:
X-AuthBypass testuser1 (http header)

This would (in special test env) bypass an otherwise extremely complicated login flow and get straight to the target page.

The alternative way to do this is adding query parameters to the URL that get read, but then the parameter ends up in server logs. It’s not particularly sensitive but don’t want it thrown around either.

I can’t find any way to do this, am I missing an option or clever trick for this? Thanks