How can you add your last year return to your new return

Are you asking about the "lookback" that allowed you to use a different year for EIC?  That is gone.  Your EIC for 2022 is based only on your 2022 income.  

Or .... are you asking how to find your 2021 AGI so you can e-file?

Where do I find my AGI?

https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947

https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/00/27010/message-id/746

Your 2021 tax return shows your 2021 Adjusted Gross Income  (AGI)  If you filed a joint return then the AGI is the same for each of you.

Form 1040        line 11

If you are using the same TT account that you used last year, you should also be able to find this number in your Tax Home for 2021

If entering the amount from your 2021tax return does not work, then try entering “0” instead.  If that does not work and you still cannot e-file, then print, sign, and mail your tax return.

You can get a free transcript of your past return from the IRS:  

https://www.irs.gov/individuals/get-transcript