it's clear to (and works for) me how to create an admin-account and login into Node-RED remotely but is there any option to grant backend-access to another person with which I don't like to share the password?
So, in other words, how can I add another backend-user into Node-RED?
Great, this helps! Worked out perfectly for me.
Just added a second user and hash in the settings.js. There you can also set read and write permissions.