Accessing Internal NeoLoad Variables in a JS

Question

I am new to NeoLoad, and I am using 9.1. After recording a script with necessary transaction names, I see Neoload creates some internal variables like NL-HttpRequestId, NL-HttpRequestPageName, etc. I want to access these variables from JavaScript. How can I do so?

I tried the below js code and placed both outside a transaction and inside, but the value is blank.

logger.debug("TXN NAME="+context.variableManager.parseString("${NL-HttpRequestTransactionName}"));