The simplest way would be to first download an Excel or CSV version of the Google sheet and [url=https://www.ragic.com/intl/en/doc/41/Importing-&-Exporting]import it manually[/url]
If you would like to do a [url=https://www.ragic.com/intl/en/doc/83/Periodic-import-from-URL]periodic import[/url], you can find the CSV feed URL of the sheet in this format:
https://docs.google.com/spreadsheets/d/DOCID/export?format=csv
Remember to replace DOCID with the actual document id, which you can find on the URL of your Google Sheet.