Sorry--it is too late. The deadline to get the first or second stimulus was May 17, 2024. If---and only if-- you could not be claimed as someone else's dependent for 2021, and you did not receive the third stimulus, you can still file a 2021 return to get the third one. You have to file -- or amend -- a 2021 return by April 15, 2025 or it will be too late for that one.
Look at your online account with the IRS to see if they sent you $1400 in 2021.
https://www.irs.gov/payments/your-online-account
If you could be claimed as someone else's dependent in 2021, you are not eligible for the payment.
If you were eligible and do not receive a payment soon from the IRS, the other way to get the payment is to r amend your 2021 return to use the recovery rebate credit before April 15, 2025. If you did not file a 2021 return at all, then prepare one and mail it in.
2021
https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
Here is the IRS 2021 Form 1040
https://www.irs.gov/pub/irs-prior/f1040--2021.pdf
or if you want bigger type use 1040SR for Seniors,
https://www.irs.gov/pub/irs-prior/f1040s--2021.pdf
And 2021 Instructions
https://www.irs.gov/pub/irs-prior/i1040gi--2021.pdf
2021 Tax and EIC Tables
https://www.irs.gov/pub/irs-prior/i1040tt--2021.pdf
Sch 1 : https://www.irs.gov/pub/irs-prior/f1040s1--2021.pdf
Sch 2 : https://www.irs.gov/pub/irs-prior/f1040s2--2021.pdf
Sch 3 : https://www.irs.gov/pub/irs-prior/f1040s3--2021.pdf
The deadline to file a 2020 tax return to claim missed second stimulus checks was May 17, 2024.
However, If you qualify but didn't file your 2021 return, you need to file it to claim the third payment/ Recovery Rebate Credit by the April 15, 2025, deadline.
Please check Here to file your 2021 return.