How can I send my in progress return to a device that has turbotax software downloaded, rather than completing the return online?

[HelenaC]

See How do I save my 2018 TurboTax Online return as a tax data file? Once it's saved to your computer, you can copy your .tax2018 file onto a flash drive or you can send your .tax2018 file through email.

Then, where ever you send it to, if you can't find the .tax2018 file, see Find your tax data file (.tax file) in Windows.