First, a payment may have been issued automatically to your bank account.
Second, if you didn't get an automatic payment, you would have claimed the credit on your 2020 and 2021 tax returns (filed in April 2021 and April 2022). The credit was added to your other refund, not issued as a separate check. While it was possible to file a tax return and not claim the credit, any software program you used would automatically claim the credit if you were eligible. So check your past tax returns to see if the credit was added to your refund.
Third, you can check your IRS account online to see if a credit or rebate was issued in your name. If it was, and you never received it, you have to trace/investigate the previous payment, you can't get a new payment by filing a new tax return. It might have been fraudulently issued in your name, or issued to the wrong bank account and sent back to the IRS, or mailed to the wrong address and sent back to the IRS.
Then finally, if you never got a payment, never claimed the equivalent credit, and a payment was never issued in your name, you can now try to claim the credit by filing amended 2020 and 2021 tax returns. If you owe a balance to the IRS and are due a stimulus credit, the credit will be applied to your back taxes first, and anything left over will be sent to you by check in the mail.
