Can't work following Readme installation

[yanbin7]

I followed the Readme file and install the plugin.The database CSV can be found after grafana restart.
However , it report errors when i configure the URL , no 'Porxy' can be choose in Access drop down-list.

[yanbin7]

And http://localhost:3003 cannot access using browser access.

sudo python /var/lib/grafana/plugins/grafana-csv-datasource/backend/PythonServer.py -f ./folders
debug False

• Serving Flask app "PythonServer" (lazy loading)
• Environment: production
  WARNING: This is a development server. Do not use it in a production deployment.
  Use a production WSGI server instead.
• Debug mode: off
• Running on http://0.0.0.0:3003/ (Press CTRL+C to quit)
  127.0.0.1 - - [16/Jan/2020 15:36:59] "GET / HTTP/1.1" 404 -
  127.0.0.1 - - [16/Jan/2020 15:37:19] "GET / HTTP/1.1" 404 -
  ./foldersfavicon.ico
  127.0.0.1 - - [16/Jan/2020 15:37:19] "GET /favicon.ico HTTP/1.1" 404 -
  ./foldersfolders
  127.0.0.1 - - [16/Jan/2020 15:38:13] "GET /folders/ HTTP/1.1" 404 -
  ./folderssample
  127.0.0.1 - - [16/Jan/2020 15:41:55] "GET /sample HTTP/1.1" 404 -
  ./folderssample
  127.0.0.1 - - [16/Jan/2020 15:43:50] "GET /sample HTTP/1.1" 404 -
  ./folderssample
  127.0.0.1 - - [16/Jan/2020 15:48:38] "GET /sample/ HTTP/1.1" 404 -