ImmortalCoordinator has this method GetLocalIPAddress which is handy, but not correct in the case where a computer has multiple ethernet interfaces (e.g. wired and wireless). In this case the user may want to specify which interface to use since they know which one is connected to the right network. You could also provide a better default which tests all available interfaces to figure out which one can reach Azure storage.
Note that CRA gets it right with CRA.Worker.exe where "An optional third parameter can be used to provide an explicit IP address."