Sorry, you cannot combine tax information prepared with the Desktop into the Online version.  You can transfer your 2019 information from your desktop to the Online version if you have a .tax file.

How do I transfer last year's return into TurboTax Online?

https://ttlc.intuit.com/community/entering-importing/help/how-do-i-transfer-last-year-s-return-into-turbotax-online/00/25953