Use https://github.com/manics/jupyter-notebookparams instead
Create a configuration file for Jupyter notebooks using URL parameters.
For example, this will create a file config.json in the default directory containing {"a":1,"b":false}, and open that file in the Jupyter editor:
This mybinder example will create the configuration file and load the example notebook. When you run the notebook the parameters will be displayed.
https://mybinder.org/v2/gh/manics/jupyter-urlparams/master?urlpath=urlparams%3Fparamsfile%3Dconfig.json%26params%3D%7B%22a%22%3A1%2C%22b%22%3Afalse%7D%26urlpath%3Dtree%252Fexample.ipynb
paramsfile: Path to the parameters file to be written
params: A string that will be written to paramsfile
urlpath: Redirect to this path after writing paramsfile
pip install .
Note it doesn't seem to be necessary to enable the extension (jupyter serverextension enable --py jupyterurlparams --sys-prefix).