An S corporation must always file its annual tax return by the 15th day of the third month following the end of the tax year, generally March 15 unless this date falls on a weekend or holiday.
You are asking from TT Home and Business. However, you must use TT Business (a different program) for an S Crop filing. This is only available as Desktop (CD/download) version, and only for Windows.
TurboTax® Business CD/Download 2020-2021 Desktop Software, File Business Taxes (intuit.com)
