For 2021 estimated tax payments made in 2020, do I need to indicate that part of the payment was from last year's federal tax refund?

Would you please clarify your question? If you made an estimated tax payment in Jan for the 2020 tax return you only need to include the estimated payment amount.

Please also see this TurboTax FAQ: How do I get credit for a 2019 refund applied to 2020's taxes? 

edited 3/24/2021