How to have the Node.js NPM Unit to make a Browser-Sync?

I have everything installed but the External that is the http that is used to enter from another device does not appear in the terminal because this happens

ALREADY INSTALL NODE.js AND INSTALL BROWSER-SYNC FROM THIS LINKS: npm install -g browser-sync AND THEN I PUT THE FOLLOWING CODE TO MAKE ME A BROWSER IN ALL THE FILES BUT THE EXTERNAL browser-sync start --server --files "css / *. Css"

The file is static but it has nothing to do