Google Sheet not showing.

That shortcode is referencing the URL at https://docs.google.com/spreadsheets/pub?key=1S2vtTJKWKh2HxvEyKzkQ7RfQOaSN-TN9waFr3WARetE which as you can see does not exist. This is what’s known as an “old style” Google Spreadsheet. From the plugin’s readme:

After setting the appropriate Sharing setting, copy the URL you use to view the Spreadsheet from your browser’s address bar into the shortcode. For example, to display the spreadsheet at https://docs.google.com/spreadsheets/d/ABCDEFG/edit, use the following shortcode in your WordPress post or page:

[gdoc key="https://docs.google.com/spreadsheets/d/ABCDEFG/edit"]

If your spreadsheet uses the “old” Google Spreadsheets, you need to ensure that your spreadsheet is “Published to the Web” and you need to copy only the “key” out of the URL. For instance, if the URL of your old Google Spreadsheet is https://docs.google.com/spreadsheets/pub?key=ABCDEFG, then your shortcode should look like this:

[gdoc key="ABCDEFG"]

The sheet you’re trying to view is a “new” Google Spreadsheet, so its URL is like this:
https://docs.google.com/spreadsheets/d/1S2vtTJKWKh2HxvEyKzkQ7RfQOaSN-TN9waFr3WARetE

During 2014, Google transitioned from the old to the new styles but some old styles remain. This plugin was first written about 5 years ago, and still supports both old and new style Google Sheets (though some advanced features only work when used with a new style google sheet).

Hope this helps.