I received $15,000 in taxable unemployment income in 2020 and needed to repay $7470 in 2021. How do I recapture the tax paid in 2020 on my 2021 tax return? Thank you.

You will enter the amount you repaid in 2021 on your tax return this year.   The first $10,200 of unemployment you received was tax free (in 2020).   When you go through the unemployment section, you will be asked about not only unemployment income you received in 2021, but also any unemployment you paid back in 2021.   

Search for unemployment and use the Jump to unemployment link in the search results.   Answer the first question yes or no and hit continue.   The next question will be about the money you repaid in 2021.   TurboTax will handle the income and tax adjustments.