If you are using docker image then after you run the container with this command:
docker run -d -p 8000:8000 --name jupyterhub jupyterhub/jupyterhub jupyterhub
bash into the running container:
docker exec -it jupyterhub bash
and then adduser test and follow the instructions. Once done then go to the browser enter:
http://localhost:8000/
Put the credentials in. It should work as it worked for me.