The calling-extensions-sdk project is a app example like build a widget that make calls on hubspot.
In this project, I change the webpack-dev-server to express, because using the first, we can't deploy on google cloud run.
I use the Mizu universal WebPhone for connect to my VOIP server.
npm run buld
npm run start
https://cloud.google.com/run/docs/quickstarts/build-and-deploy/deploy-nodejs-service
For this, you can follow steps on: https://github.com/HubSpot/calling-extensions-sdk