that port is alread y in use mac code example
Example 1: stop port 3000 mac
sudo lsof -i :3000
kill -9 PID
Example 2: mac terminal find process by port
sudo lsof -i tcp:3000
Example 3: killing a port mac
kill -9 <PID>
sudo lsof -i :3000
kill -9 PID
sudo lsof -i tcp:3000
kill -9 <PID>