Nexus Not Parsing HTTP Basic Auth

I am trying to get Nexus Webhooks working with Jenkins. We cannot allow our Jenkins system to allow anonymous access, thus we need some sort of authentication (using account credentials or an API key).

We have tried using HTTP basic authentication (http://username:password@server) and Nexus does not seem to be capable of parsing out that information and updating the request going out. So, when Jenkins gets the request it does not see any authentication in the headers, and responds with a 403. I confirmed that this authentication method works by sending the same URL to Jenkins using a simple Python request script. The header is properly updated with the authentication information and Jenkins accepts the request.

Is there some setting we need to flip to get this parsing working, a special flag (or library) we need to use when building / installing Nexus or is this capability just not provided / supported? If it is not available, are there any plans to add it?

verifying the hmac should identify the source - Example Headers And Payloads

Identifying the source is not the problem. Because our systems are behind auth walls, the request needs to contain credentials. I understand that the X-Nexus-Webhook-Signature header would be where credentials or a key would be, however, Jenkins does not currently support that header: