How to access single user notebook in a web browser in API only mode?

JupyterHub
2

I suspect you are hitting this error, where cookie auth is not persisted from a token-in-url-authenticated request when using the new jupyterhub server extension. The workaround while waiting for a release is to use the older subclass implementation of jupyterhub-singleuser by setting JUPYTERHUB_SINGLEUSER_EXTENSION=0.