Why am I getting this Error: listen EADDRINUSE: address already in use 127.0.0.1:80 code example

Example 1: listen EADDRINUSE: address already in use 127.0.0.1:8000

sudo lsof -i :3000

Example 2: Uncaught Error: listen EADDRINUSE: address already in use 0.0.0.0:3000

C:\Users\admin>netstat -ano|findstr "PID :3000"

taskkill /pid 18264 /f