Adding external service in the service graph

Hey, I have ad service called “A” which will receive triggers from the external service which is not instrumented. How can represent that service name is the service graph. i am able to add it in the service graph , but i am not able to modify the default it is taking it is “user”. How can i modify this node name.

Can you use value mapping?

Hi,
can you please tell me how can i achieve this value mapping. i would be very thankful of your reply.