Yes you can transfer from Online to Desktop or Desktop to Online. You could have transferred 2020 online into the 2021 desktop program. Did you ask for help? Which way do you need to go for 2024?
If you used the Desktop program last year here’s How to transfer into the Online version. You need to have the prior year .tax2023 file on your computer. Expand the link if you used the CD/download last year........
https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/transfer-last-y...
You can transfer your return from Online to the Desktop installed program. Starting in 2023 there are new buttons when you start a new Desktop return. You can Continue from Online or Import from last year's Online return. So look for those.