Why did my office add-in NPM fail to start? Can you check it for me please?

Question

My program is written step by step in accordance with official documents, and so is the command.Port 3000 is not used. Why can't I start port 3000?

E:\My Office Add-in>npm start

> [email protected] start E:\My Office Add-in
> office-addin-debugging start manifest.xml

Debugging is being started...
App type: desktop
Enabled debugging for add-in af71531f-d6c5-4ff3-854d-7b8dc52e3dcd. Debug method: 0
Starting the dev server... (webpack-dev-server --mode development)
Unable to start the dev server. Error: The dev server is not running on port 3000.
Sideloading the Office Add-in...
Debugging started.

enter image description here

Answer 1

I had almost the exact same problem, and I fixed it using sudo:

sudo npm start