Hi Suvasis - apologies for the delay here!
Looking through the code you'd shared, it looks like you'd set up a tracer provider to send traces to http://localhost:4318
You'd need to be running a service to receive and visualize traces sent to that endpoint. Phoenix is our open-source tool for this. Jaeger UI would be another option.
I can't speak to Jaeger UI as much, but do you have one of these tools running on localhost:4318 to receive the traces you're generating?