Change default port number for gcp cloud run emulator

I am using cloud run emulator for local development with VS code (https://cloud.google.com/code/docs/vscode/develop-service)

I see the forwarded URL from cloud run service: http://localhost:8080

How can I change the port number? For example from 8080 to 8081

I hoped this could be done by changing the containerPort parameter in the lauch.json file.