Login Page for user

I am a newbee... so don't know a lot.
I want to make login and password. if user enters correct password then user can access dashboard. I am using Node-RED IBM cloud.

I am trying but don't know the correct way.

Have you read the Node-RED documentation site? There are instructions there.

Bear in mind though that the Node-RED Dashboard is not a multi-user system in the traditional sense, it isn't directly designed to handle multiple differently secured users on the Dashboard.