I installed conda install -c conda-forge jupyter_nbextensions_configurator and ran jupyter nbextensions_configurator enable --user in my venv, but the nbextensions menu is empty. I've restarted notebook a few times, no luck. How can I get the menu to show up so that I can click and select TOC, etc.?
System details:
Windows 10, Firefox 
conda   4.8.2  
Python  3.8.3 
jupyter 1.0.0   pypi_0  pypi 
jupyter_client  6.1.3   py_0    conda-forge 
jupyter_console 6.1.0   py_1    conda-forge 
jupyter_contrib_core    0.3.3   py_2    conda-forge 
jupyter_core    4.6.3   py38h32f6830_1  conda-forge 
jupyter_nbextensions_configurator 0.4.1 py38_0  conda-forge 
(myenv) C:\path>jupyter nbextension list
Known nbextensions:
  config dir: C:\path\.jupyter\nbconfig
    notebook section
      nbextensions_configurator/config_menu/main enabled
      - Validating: problems found:
        - require?  X nbextensions_configurator/config_menu/main
      jupyter-js-widgets/extension disabled
      jupyter-vega/index disabled
    tree section
      nbextensions_configurator/tree_tab/main enabled
      - Validating: problems found:
        - require?  X nbextensions_configurator/tree_tab/main
  config dir: C:\path\anaconda3\envs\myenv\etc\jupyter\nbconfig
    notebook section
      jupyter-js-widgets/extension enabled
      - Validating: ok
      jupyter-vega/index enabled
      - Validating: problems found:
        - require?  X jupyter-vega/index
      nbextensions_configurator/config_menu/main enabled
      - Validating: problems found:
        - require?  X nbextensions_configurator/config_menu/main
    tree section
      nbextensions_configurator/tree_tab/main enabled
      - Validating: problems found:
        - require?  X nbextensions_configurator/tree_tab/main


