In your Google Sheet, go to File > Publish to the Web…
Click [Publish] and click [OK] on the pop-up box.
Don’t use the URL provided in this window, instead exit out of this dialog box.
Now copy the URL from your address bar, and paste the URL into the Sheet ID or URL field of the Arreya Google Sheets Data widget.
Input which cell you’d like to pull data from, and press [OK]. A widget will now be inserted with your Google Sheets data.