node is using port 3000 code example
Example 1: npm port already in use
$ lsof -i tcp:3000
$ kill -9 PID
Example 2: Port 3000 is already in use, but when I try to kill nothing is found
netstat -ano | findstr :3000
taskkill /PID "123" /F
$ lsof -i tcp:3000
$ kill -9 PID
netstat -ano | findstr :3000
taskkill /PID "123" /F