If on my tax return the Recovery Rebate Credit does not reflect the 3rd stimulus. Do I need to amend my return to reflect the correct total?

[xmasbaby0]

No.   Your 2020 tax return is not going to show anything about the 3rd stimulus and never will.   The 3es stimulus check is an event in 2021.  You only enter the amounts received for round #1 and round #2 of the stimulus checks issued in 2020 and early 2021 to you.

You can use the IRS Get My Payment site to see what is expected for your 3rd stimulus check:

https://www.irs.gov/coronavirus/get-my-payment

[DoninGA]

The Recovery Rebate Credit for the 2020 federal tax return will Not have the third stimulus payment included.

Go to this IRS website for the third stimulus get my payment - https://www.irs.gov/coronavirus/get-my-payment