How to use npm 'concurrently'

I have a React App, with a Node.js backend. On the server I'm forwarding the request to other servers. The structure looks like this:

MyApp (folder)

-client(react)

-server(node.js)

MicroServers (folder)

-micro-server1(node.js)

-micro-server2(node.js)

-more

How do I use cincurrently to start all the micro-servers at the same time? Where do I install it? from where do I run it?

Thanks a lot!

via code83