I assume you mean false as per the screenshot?
When its sent to false, the library sends the request without any auth info attached. The 401 response it gets back from the server will include the type of auth required, so the library can resubmit the request with the appropriate auth header.
So it works, but it takes two requests over the network. So I don't think we can afford to hard code it in - by definition, all flows that successfully use auth with the node today will be penalised.
That does mean it would need to be exposed as an option in the UI, but at this point of a Friday night, I don't know what that should look like.
A tick box for 'send immediately' doesn't really help the user understand what it means - I had to read the 3 paragraphs of the request module's readme a couple times to understand what it meant.
Maybe a select box for the type of auth - which could be expanded to include Bearer (something that can be done today by setting msg.headers.authorization to the right value before the HTTP Request node). Needs more thought about what the different options mean and what they would require the node to actually do.
