Create environment linux with several users

I’m a teacher, and I achieve to build an environment with bash kernel. So, my students can try shell command without linux installed at home. But they can’t test the rights of files and directories.
So, I want to create an environment with several users. My student could switch one to another to test file rights.
I’ve tried to put : adduser in a start file, but users are not created.
If someone has an idea?

You posted this in the Binder category. I’ll assume you are using the public Binderhubs (via and not your own install?

Public binders run in singleuser mode as far as I know. So that you cannot add users. (I wonder if you could add them in during the image build if you used a Dockerfile for your configuration?) Plus you don’t have root access.