Unfortunately, you can't open TurboTax Online returns in TurboTax CD/Download. TurboTax Online can't create .tt files, which is what TurboTax CD/Download uses.

You can still print or download a PDF copy of your TurboTax Online return. Please see this TurboTax FAQ for instructions: In the online edition of TurboTax, how do I print a copy of my tax return?

Thank you for choosing TurboTax.

Once you pay for the return, you will be granted access to save the PDF file to your computer.
On your TurboTax Online return, scroll to the bottom of the left-hand column on the screen, and select FILE > Print Your Tax Return. Then select the option to save a PDF copy.
(Note: TurboTax Free users don’t have to pay to print a tax return, but will still need to go through the payment section to reach the print option.)

For more information, please see our TurboTax FAQ:

How do I print/save a copy of my return in TurboTa... (intuit.ca)

Thank you for choosing TurboTax.