If you started the 2019 return online and want to finish in the 2019 downloaded version :
https://ttlc.intuit.com/questions/1901476-how-do-i-switch-from-turbotax-online-to-the-turbotax-softw...
If you did NOT start the 2019 return online yet and just need to transfer the 2018 info to the 2019 downloaded program ...
https://ttlc.intuit.com/community/entering-importing/help/how-do-i-transfer-last-year-s-return-into-...
