How to run the demo in agent-js?

I read the README.md file in the demo / sample-javascript folder.

The server works but returns this error:
ERROR in ./src/main.js 1: 0-72
Module not found: Error: Can’t resolve ‘…/…/…/node_modules/@dfinity/agent’ in ‘/ home / me / agent-js / demos / sample-javascript / src’

Can you help me? Thank you