It may not have been that same amount as you have on line 30 ... look for a deposit from the IRS for "EIP3" starting in March of 2021 thru the end of the year. It is possible that you got more than one deposit so review the entire year. Also check your account transcript on the IRS website to see how much was sent and when ...
https://www.irs.gov/individuals/get-transcript
https://www.irs.gov/newsroom/recovery-rebate-credit
If you did not receive $1,400 for the third stimulus payment, the IRS may think that you were already issued the third stimulus payment.
At your IRS online account, you can find whether a payment was issued to you that you did not receive. You can also find this information on your tax transcript.
If you need to trace a payment that the IRS says has been issued to you, mail or fax a completed IRS Form 3911, Taxpayer Statement Regarding Refund.
