How can I import the last year tax return into this year tax return

How did you do it last year?  Online version or the Desktop program?   What do you want to transfer it into?  Do you have the .tax2020 file on your computer?

How to transfer into the Online version

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

How to transfer into Windows Desktop

https://ttlc.intuit.com/community/entering-importing/help/transfer-last-year-s-return-to-turbotax-for-windows/00/26145

How to transfer into Mac Desktop

https://ttlc.intuit.com/community/tax-data-file/help/how-do-i-transfer-last-year-s-return-into-the-turbotax-for-mac-software/00/26062