npm run dev something is already running on port 3000 code example
Example 1: how to close port 3000 running
### For Linux/Mac OS search (sudo) run this in the terminal:
$ lsof -i tcp:3000
$ kill -9 PID
### On Windows:
netstat -ano | findstr :3000
tskill typeyourPIDhere
### change tskill for taskkill in git bash
Example 2: stop npm running on port 3000
netstat -ano | findstr :3000
taskkill /F /PID PID_of_port