SOAP UI - Basic Authentication - where do I find it in Server Code?

I have a SOAP Server written in PHP - and am Testing using SOAP UI. Everything works fine and returns results as expected.

I am now trying to add in Basic Authentication - have set up in SOAP UI with Username and Password - BUT can't find how to check it in the Server code?

I was expecting the credentials to be in the [SERVER] object passed to the server - but they are not.