curl: (7) Failed to connect to localhost port 3000: Connection refused
I think it's because you have not started your local host with port 3000.
Try http://localhost:3000/ in your browser. See if it's connected.
If not, you need to start your local host first with port 3000.
I think port 3000 is not open on the host. To see if something is listening on a certain port or open at all, you can use netstat -tlpen | grep 8080 or nc -vz [host] [port].