Enable the Google Sheets API at Step1 of the Google Node.js Quickstart tutorial and download the Client Configuration file.
Copy the Client Configuration from the file downloaded in the previous step, paste it into the text box, and hit Enter. to save it in the config database collection.
Create a Google Sheet. Copy the URL from the browser's address bar and paste into the text box. Hit Enter to save the Sheet Id in the config database collection.
When the Get Code button is enabled, click to open the Google page to authorize the app. After the app is authorized, copy the authorization code from the page.
Paste the authorization code into the text box and hit Enter. This will generate a refresh token which will be saved to the config database collection.
After completing the configuration process, go to the Home page of this app and save some data to your Google Sheet.
Click Reset if you wish to reset the configuration and start the process over again. This will clear the configuration data currently saved in the database.