Answers for "no link for javascript in html"

kill all server 5000 mac

#First run this, to get port information (with the port you want to kill)
sudo lsof -i :3000 

#Then run this, with <PID> replaced by the value in the column returned by previous command.
kill -9 <PID>

kill a port

kill $(lsof -ti:3000)

how to link your js file to html

<script src="index.js"></script>

how to link javascript to html

<script src = "index.js"></script>