You can print and mail the tax return. There are no penalties for filing a tax return after the due date if the tax return is being filed for a tax refund or there are no taxes owed.
See this TurboTax support FAQ for the procedure to print a tax return for mailing when using the online editions - https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online...
