Error in running Amp-pwa sample

Could not find a required file.
Name: index.html
Searched in: /home/user_name/Desktop/web/samples/amp-pwa/public

npm ERR! Linux 4.15.0-43-generic
npm ERR! argv "/usr/bin/node" "/usr/bin/npm" "start"
npm ERR! node v8.10.0
npm ERR! npm v3.5.2
npm ERR! code ELIFECYCLE
npm ERR! amp-pwa@0.1.0 start: `react-scripts start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the amp-pwa@0.1.0 start script 'react-scripts start'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the amp-pwa package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! react-scripts start
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs amp-pwa
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls amp-pwa
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR! /home/user_name/Desktop/web/samples/amp-pwa/npm-debug.log