How to use the voila.paths.jupyter_path function in voila

{
                'whitelist': voila_configuration.file_whitelist,
                'blacklist': voila_configuration.file_blacklist,
                'path': os.path.expanduser(web_app.settings['server_root_dir']),
            },
        ),
    ])

    # Serving notebook extensions
    if voila_configuration.enable_nbextensions:
        # First look into 'nbextensions_path' configuration key (classic notebook)
        # and fall back to default path for nbextensions (jupyter server).
        if 'nbextensions_path' in web_app.settings:
            nbextensions_path = web_app.settings['nbextensions_path']
        else:
            nbextensions_path = jupyter_path('nbextensions')

        web_app.add_handlers(host_pattern, [
            # this handler serves the nbextensions similar to the classical notebook
            (
                url_path_join(base_url, r'/voila/nbextensions/(.*)'),
                FileFindHandler,
                {
                    'path': nbextensions_path,
                    'no_cache_paths': ['/'],  # don't cache anything in nbextensions
                },