When you begin your 2021 return you are asked if you want to transfer data from 2020 to 2021. If you choose to transfer the old tax year to the new return the charity information will transfer over with your other 2020 data. That transfer has to be done at the very beginning before you start to enter any other 2021 data into the new return.
How to transfer last year’s return? https://ttlc.intuit.com/questions/1900883
First all the cash donations can be entered as one amount as VARIOUS since the IRS doesn't get the individual entries on the Sch A at all.
You could use the IT'S DEDUCTIBLE tool and import from there ... use the same sign in info when you set up the account and it will transfer into the TT program easily : https://itsdeductibleonline.intuit.com/
Re: How can I transfer all my information on my 2020 tax return to my 2021 tax return. My 2020 tax information was on CA-2020-tax file
What tax program did you use for the 2020 return ? And what is the extension of the file you want to transfer ? Is it a .taxfile ?
If you used Turbo Tax online for 2020 just log into the same exact account.
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
If you used the Desktop program last year you need the file ending in .tax2020 on your computer
How to Transfer into the Windows Desktop program
https://ttlc.intuit.com/community/entering-importing/help/transfer-last-year-s-return-to-turbotax-for-windows/00/26145
How to Transfer into the Mac Desktop program
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