When you open your .gsheet link in Google Drive to access the Google Spreadsheet spreadsheet, you can download the file in CSV format using the File ► Download as function in the upper menu. This means you will need access to Internet to perform gsheet to csv export, because without Google Drive, you won't be able to access the spreadsheet. Except for this, there is no other way how to otherwise convert gsheet to csv.
Open GSHEET file Open CSV file