That sounds like the generic letter listing reason why they adjusted the Recovery Rebate Credit on 1040 line 30. How much is on your tax return line 30? When Turbo Tax asked, did you enter the amount you already got?
Did you not get the 3rd Stimulus payment for 1400 per person? Or qualify for more? Line 30 is only if you didn't get the full amount or qualify for more. The IRS shows they already sent it to you.
Double check your bank statements and Check your IRS account (both accounts if married)
Your Online Account | Internal Revenue Service
If the IRS thinks they sent it to you but you didn't get it request a trace for a missing third Stimulus payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-p...
