403B Cares Act withdrawal and repayment over three years

I took out $20,000 from my 403B in 2020 to assist with Covid expenses. Last year I had the option of repaying the taxes back over 3 years. Last year, I thought the first payment came off of my tax return, but now I am questioning if I was to pay that back through the estimated quarterly taxes. So, now I should be having my second payment, but do not see that it was factored into my taxes. I want to make sure I am getting this paid back, so there are no surprises next year. Does anyone have any thoughts or information to assist? Thank you.