title: How to install jupyterlab extension behind corporate proxy?
body: <p>I am trying to install jupyterlab extension behind a corporate proxy.
  I have manged to configure the <code>npm</code> config using following commands:</p>
  <pre><code>npm config set proxy http://username:password@host:port
  npm config set https-proxy http://username:password@host:port
  </code></pre>
  <p>And it seems package has been downloaded however I am still getting following error:</p>
  <p><code>Failed to fetch package metadata for 'jupyterlab-plotly': URLError(ConnectionResetError(10054, 'An existing connection was forcibly closed by the remote host', None, 10054, None))</code></p>
  <p>How to solve this issue?</p>